How to use SOH CAH TOA: Geometry

Welcome back to Mathsux! This week, we’re going to go over how to find missing angles and side lengths of right triangles by using trigonometric ratios (sine, cosine, and tangent) (aka how to use SOH CAH TOA).  Woo hoo! These are the basics of right triangle trigonometry, and provides the base for mastering so many more interesting things in trigonometry! So, let’s get to it!

Also, if you have any questions about anything here, don’t hesitate to comment below or watch the video below. Also, don;r forget to subscribe to Math Sux for FREE math videos, lessons, and practice questions every week. Happy calculating! 🙂

How to use SOH CAH TOA?

Trigonometric Ratios (more commonly known as Sine, Cosine, and Tangent) are ratios that naturally exist within a right triangle.  This means that the sides and angles of a right triangle are in proportion within itself.  It also means that if we are missing a side or an angle, based on what we’re given, we can probably find it!

Let’s take a look at what Sine, Cosine, and Tangent are all about!

How to use SOH CAH TOA
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Now let’s see how we can apply trig ratios when there is a missing side or angle in a right triangle!

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How to use SOH CAH TOA
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How to use SOH CAH TOA
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How to use SOH CAH TOA

Now for another type of question; using trig functions to find missing angles, let’s take a look:

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How to use SOH CAH TOA

Try the following Practice Questions on your own!

How to use SOH CAH TOA


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Still got questions?  No problem! Check out the video the same examples outlined above and happy calculating! 🙂

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Need to brush up on special right triangles? Check out this posts on the 45 45 90 special triangles here!