Trigonometric Ratios and Finding Missing Sides
Trigonometric ratios like sine, cosine, and tangent are fractions that relate the sides of a right triangle to its angles. For any angle in a right triangle, these ratios remain consistent regardless of the triangle's size.
To find a missing side of a right triangle, you'll need to identify which trig ratio to use based on what you know. If you know an angle and the hypotenuse, use sine or cosine. If you know an angle and one leg, tangent often works best. Simply substitute your known values into the appropriate formula and solve.
For example, if you know a triangle has a 48° angle and a side adjacent to that angle measuring 17 units, you can find the opposite side using tangent: tan(48°) = x/17, so x = 17 × tan(48°) = 18.9 units.
Quick Tip: Remember SOH-CAH-TOA to keep the ratios straight: Sine = Opposite/Hypotenuse, Cosine = Adjacent/Hypotenuse, Tangent = Opposite/Adjacent.
When solving problems, follow these steps: (1) identify what you know and what you need to find, (2) determine which trig ratio relates these values, (3) set up an equation, and (4) solve for the missing value. Most problems will have you round to the nearest tenth.