Finding a Missing Side of a Right Triangle

November 4, 2016 — Leave a comment

To find a missing side of a right triangle, you’ll need 1 side and 1 angle.
To find a missing angle of a right triangle, you’ll need 2 sides.

There are 2 ways to solve for a missing side of a right triangle. By using either SOH CAH TOA or if there are already 2 sides, you can use pythagorean theorem.

First, label the sides in respect of the angle you’re using. Once you’ve labeled decide which trig function to use.

SOH       CAH       TOA
(Sin: \frac{O}{H}) (Cos: \frac{A}{H}) (Tan: \frac{O}{A})

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To solve this equation I will be using Cos for we’re looking for adjacent and we have the hypotenuse. Cosine: \frac{A}{H}

\cos45^\circ=\frac{x}{36}
(36) \cos45^\circ=\frac{x}{36} (36)
(36) \cos45^\circ = x
x = (36) \cos45^\circ
x = 24.7487 cm
x = 25cm (rounding to the nearest cm)

 

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