{"id":460,"date":"2022-03-02T14:08:29","date_gmt":"2022-03-02T14:08:29","guid":{"rendered":"https:\/\/visualfractions.com\/blog\/?p=460"},"modified":"2023-02-23T17:03:27","modified_gmt":"2023-02-23T17:03:27","slug":"3-4-5-triangles","status":"publish","type":"post","link":"https:\/\/visualfractions.com\/blog\/3-4-5-triangles\/","title":{"rendered":"3, 4, 5 Triangles"},"content":{"rendered":"\n<p>The 3-4-5 right triangles are special right triangles that exhibit a unique Pythagorean triple for their side lengths ratio. Knowing what makes these triangles special will simplify the process of solving right triangles\u2019 measures and word problems involving these triangles. The 3-4-5 right triangles will also help refresh your understanding of the Pythagorean theorem and triples.<\/p>\n\n\n\n<p>In this article, understand the properties that define 3-4-5 right triangles and learn how to identify these triangles by inspecting their sides. Explore the different problems involving 3-4-5 right triangles and know their properties by heart here. Feel confident when working with these triangles by the end of this discussion!<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Is a 3 4 5 Right Triangle?<\/h2>\n\n\n\n<p>The 3-4-5 triangle is a special type of right triangle with side lengths sharing a specific ratio: 3:4:5, where the third component represents the length of its hypotenuse. Since the right triangle will always have this special ratio, all 3-4-5 triangles will always have three different integer side lengths. This means that 3-4-5 right triangles are scalene right triangles.&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"448\" height=\"291\" src=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image.png\" alt=\"\" class=\"wp-image-461\" srcset=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image.png 448w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-300x195.png 300w\" sizes=\"auto, (max-width: 448px) 100vw, 448px\" \/><\/figure>\n\n\n\n<p>The most basic 3-4-5 triangle is the right triangle with the following side lengths: 3 inches, 4 inches, and 5 inches. All right triangles will satisfy the Pythagorean theorem, so the 3-4-5 right triangle is no exception. The Pythagorean theorem states that the sum of the sides\u2019 squares must be equal to the square of the right triangle\u2019s hypotenuse.&nbsp;<\/p>\n\n\n\n<p>[katex]\\begin{aligned}a^2 + b^2 &amp;= c^2\\\\ (3)^2 + (4)^2 &amp;= (5)^2\\\\ 9 +16&amp;= 25\\\\25 &amp;\\overset{\\checkmark}{=} 25 \\end{aligned}[\/katex]<\/p>\n\n\n\n<p>As expected, the right triangle shown above satisfies the Pythagorean theorem. This is true for all 3-4-5 right triangles.&nbsp; As long as the sides of a scalene right triangle reduce to a ratio of 3:4:5, the triangle is a 3-4-5 right triangle. Before generalizing the process of finding these triangles, take a look at the right triangle shown below first.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"409\" height=\"285\" src=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-1.png\" alt=\"\" class=\"wp-image-462\" srcset=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-1.png 409w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-1-300x209.png 300w\" sizes=\"auto, (max-width: 409px) 100vw, 409px\" \/><\/figure>\n\n\n\n<p>Observe the side lengths of the right triangle: 9 cm, 12 cm, and 15 cm. Write down the ratio of the sides then simplify to see if it is also a 3-4-5 right triangle.&nbsp;<\/p>\n\n\n\n<p>[katex]9 : 12: 15 = 3: 4 : 5[\/katex]<\/p>\n\n\n\n<p>By simplifying the ratio of the triangle\u2019s side, we can confirm that the triangle is indeed a 3-4-5 right triangle. As expected, this 3-4-5 right triangle also satisfies the Pythagorean theorem.&nbsp;<\/p>\n\n\n\n<p>[katex]\\begin{aligned}a^2 + b^2 &amp;= c^2\\\\ (9)^2 + (12)^2 &amp;= (15)^2\\\\ 81 +144&amp;= 225\\\\225 &amp;\\overset{\\checkmark}{=} 225 \\end{aligned}[\/katex]<\/p>\n\n\n\n<p>In fact, all 3-4-5 right triangles showcase side lengths that are Pythagorean triples. This means that knowing why and how to identify Pythagorean triples is helpful when working with 3-4-5 right triangles.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Pythagorean Triples and 3 4 5 Right Triangles<\/strong><\/h2>\n\n\n\n<p>The side lengths of a 3-4-5 right triangle are always Pythagorean triples&#8211; these are set of integers that satisfy the Pythagorean theorem.&nbsp; Similar to other Pythagorean triples, the multiples of the set, [katex]\\{3, 4, 5\\}[\/katex], will also be side lengths of 3-4-5 right triangles. This means that when a right triangle has any of these Pythagorean triples, it is going to be a 3-4-5 right triangle.&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td colspan=\"3\"><strong>Pythagorean Triples<\/strong><\/td><\/tr><tr><td>{3, 4, 5}<\/td><td>{6, 8, 10}<\/td><td>{9, 12, 15}<\/td><\/tr><tr><td>{12, 16, 20}<\/td><td>{15, 20, 25}<\/td><td>{18, 24, 30}<\/td><\/tr><tr><td>{21, 28, 35}<\/td><td>{24, 32, 40}<\/td><td>{27, 36, 45}<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>This table can go on endlessly since any factor can be multiplied to each of the values from {3, 4, 5} to form a new set of a Pythagorean triple. Suppose that <em>n<\/em> is a positive factor, the Pythagorean triple, [katex]\\{3n, 4n, 5n\\}[\/katex] represents the sides of a 3-4-5 right triangle.&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"398\" height=\"296\" src=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-2.png\" alt=\"\" class=\"wp-image-463\" srcset=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-2.png 398w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-2-300x223.png 300w\" sizes=\"auto, (max-width: 398px) 100vw, 398px\" \/><\/figure>\n\n\n\n<p>The triangle shown above is the general form of the 3-4-5 right triangle. As with all right triangles, the general form satisfies the Pythagorean theorem as well. Substitute these side lengths in terms of <em>n<\/em> into the Pythagorean theorem\u2019s equation.<\/p>\n\n\n\n<p>[katex]\\begin{aligned}a^2 + b^2 &amp;= c^2\\\\ (3n)^2 + (4n)^2 &amp;= (5n)^2\\\\ 9n^2 +16n^2 &amp;= 25n^2\\\\25n^2 &amp;\\overset{\\checkmark}{=} 25n^2 \\end{aligned}[\/katex]<\/p>\n\n\n\n<p>This confirms that the side lengths of any 3-4-5 right triangle will always be a Pythagorean theorem. In addition, we can find different side lengths for a 3-4-5 right triangle by multiplying the Pythagorean triple, {3, 4, 5}, by a positive integer.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Problem 1<\/h3>\n\n\n\n<p>Apply what you\u2019ve learned in this section to identify the 3-4-5 right triangles among the five right triangles shown below.&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1017\" height=\"445\" src=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-3.png\" alt=\"\" class=\"wp-image-464\" srcset=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-3.png 1017w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-3-300x131.png 300w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-3-768x336.png 768w\" sizes=\"auto, (max-width: 1017px) 100vw, 1017px\" \/><\/figure>\n\n\n\n<p>To confirm that a given right triangle is a 3-4-5 right triangle, find the ratios of the side lengths then see if they reduce to 3:4:5. If the ratio reduces to 3:4:5, we can confirm that the triangle is indeed a 3-4-5 right triangle. The table below summarizes the side length ratios of the five triangles.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td><strong>Triangle A<\/strong><\/td><td>[katex]6:8:10 = 3:4:5[\/katex]<\/td><\/tr><tr><td><strong>Triangle B<\/strong><\/td><td>[katex]10:24:26 = 5:12:13[\/katex]<\/td><\/tr><tr><td><strong>Triangle C<\/strong><\/td><td>[katex]30: 40:50 = 3:4:5[\/katex]<\/td><\/tr><tr><td><strong>Triangle D<\/strong><\/td><td>[katex]18 :24:30 = 3: 4 :5[\/katex]<\/td><\/tr><tr><td><strong>Triangle E<\/strong><\/td><td>[katex]10:30:34 = 5:15:17[\/katex]<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>There are only two triangles with side length ratios not equal to 3:4:5 \u2013 these are triangles B and E.&nbsp; This means that the remaining triangles are 3-4-5 right triangles. Hence, triangles A, C, and D are all 3-4-5 right triangles. Now that we\u2019ve established the rules for identifying 3-4-5 right triangles, it\u2019s time to expand our understanding and learn how to apply them when solving unknown measures and problems.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How To Solve 3 4 5 Right Triangle Problems?<\/h2>\n\n\n\n<p>Utilize the common ratio that 3-4-5 right triangles share when solving problems involving them. When looking for an unknown measure of a 3-4-5 right triangle, identify the side that corresponds with the ratio\u2019s component. Simplify the process of solving problems by utilizing the Pythagorean triple, {3, 4,5}, and its corresponding multiples.<\/p>\n\n\n\n<p>In this section, we\u2019ll cover some examples showing how helpful 3-4-5 right triangles can be when solving problems. When dealing with 3-4-5 right triangles, knowing their properties will make a difference. Here are the properties of 3-4-5 right triangles that will come in handy later on:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>The 3-4-5 right triangles will always have three unequal sides that share a common ratio of 3:4:5.<\/li><li>The three side lengths of 3-4-5 right triangles will always be Pythagorean triples that are multiples of {3, 4, 5}.<\/li><li>All 3-4-5 right triangles will have interior angles with measures of 36.87<sup>o<\/sup>, 53.13<sup>o<\/sup>, and 90<sup>o<\/sup>.<\/li><\/ul>\n\n\n\n<p>Utilizing these properties simplifies the steps for solving unknown measures of a right triangle. Learn how without using Pythagorean\u2019s theorem, it\u2019s still possible to solve and work with these special right triangles.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Problem 2<\/h3>\n\n\n\n<p>A right triangle has a leg that measures 48 cm and a hypotenuse that is 80 cm long. What is the length of the right triangle\u2019s remaining leg?<\/p>\n\n\n\n<p>When working with problems like this, the first thing to do is to confirm that we\u2019re working with a 3-4-5 right triangle. To do so, find the ratio of the two remaining sides to see if they simply to two components of 3:4:5 with 80 cm corresponding to the third ratio component.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"502\" height=\"338\" src=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-4.png\" alt=\"\" class=\"wp-image-465\" srcset=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-4.png 502w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-4-300x202.png 300w\" sizes=\"auto, (max-width: 502px) 100vw, 502px\" \/><\/figure>\n\n\n\n<p>Let <em>h<\/em> be the unknown leg of the right triangle, so the ratio of the right triangle\u2019s side lengths is <em>h: <\/em>48: 80. When simplified, the ratio of the three sides becomes <em>h\/16 <\/em>: 3: 5. This crosses off our condition \u2013 the simplified ratio must have at least two components of 3: 4: 5.&nbsp;<\/p>\n\n\n\n<p>[katex]h: 48: 80 = \\dfrac{h}{16}: 3: 5[\/katex]<\/p>\n\n\n\n<p>Rearranging the ratio of the right triangle\u2019s side lengths, we have 3: <em>h\/16<\/em> : 5.&nbsp; This means that the unknown leg represents the 3-4-5 right triangle\u2019s side that is a multiple of 4. To find the value of <em>h<\/em>, simply equate <em>h\/16<\/em> to 4.<\/p>\n\n\n\n<p>[katex]\\begin{aligned}\\dfrac{h}{16} &amp;= 4\\\\h &amp;= 4(16)\\\\ h&amp;= 64\\end{aligned}[\/katex]<\/p>\n\n\n\n<p>This means that the unknown leg\u2019s length is 64 cm. We can confirm this by seeing if the side lengths reduce to 3:4:5.<\/p>\n\n\n\n<p>[katex]\\begin{aligned}48: 64:80 = 3: 4: 5\\end{aligned}[\/katex]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Problem 3<\/h3>\n\n\n\n<p>A rectangle is formed by two right triangles as shown below. What is the diagonal of the rectangle?<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"537\" height=\"320\" src=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-5.png\" alt=\"\" class=\"wp-image-466\" srcset=\"https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-5.png 537w, https:\/\/visualfractions.com\/blog\/wp-content\/uploads\/2022\/03\/image-5-300x179.png 300w\" sizes=\"auto, (max-width: 537px) 100vw, 537px\" \/><\/figure>\n\n\n\n<p>The diagonal of the rectangle is also the hypotenuse of each of the right triangles. Now, let <em>h<\/em> represent the hypotenuse of the right triangle. Observe the ratio of the right triangle\u2019s sides first to see if we can apply the properties of 3-4-5 triangles for this problem.<\/p>\n\n\n\n<p>[katex]27: 36: h = 3: 4: h[\/katex]<\/p>\n\n\n\n<p>Since the legs of the right triangle have side lengths with a ratio of 3:4, we\u2019re working with a 3-4-5 right triangle. The common factor shared between the legs is 9, so <em>h<\/em> must also share this as a common factor along with 5 as another factor.&nbsp;<\/p>\n\n\n\n<p>[katex]\\begin{aligned}h &amp;= 9(5)\\\\&amp;= 45\\end{aligned}[\/katex]<\/p>\n\n\n\n<p>This means that the value of <em>h<\/em> is equal to 45 inches. We can also confirm this by simplifying 27:36:45 \u2013 it returns a ratio of 3:4:5. Hence, the diagonal of the rectangle is also 45 inches long.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In this article, we will cover the properties that define 3, 4, 5 triangles and learn how to identify these triangles by inspecting their sides and angles.<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-460","post","type-post","status-publish","format-standard","hentry","category-geometry"],"_links":{"self":[{"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/posts\/460","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/comments?post=460"}],"version-history":[{"count":2,"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/posts\/460\/revisions"}],"predecessor-version":[{"id":470,"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/posts\/460\/revisions\/470"}],"wp:attachment":[{"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/media?parent=460"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/categories?post=460"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/visualfractions.com\/blog\/wp-json\/wp\/v2\/tags?post=460"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}