Finding Missing Sides

Trigonometry · Axiom Academy

EXAMPLE Finding Missing Sides in Right Triangles Learn to select the appropriate trigonometric function to find unknown sides using one angle and one side. Excellent work! You've successfully found all missing sides using trigonometric functions. Here's what we learned: Label Sides First: Always identify which side is opposite, adjacent, and hypotenuse relative to the given angle. Choose the Right Function: Use SOH-CAH-TOA to select the correct trig function based on which sides you have and which you need: Sin = Opposite/Hypotenuse Substitute and Solve: Plug in your known values and solve algebraically for the unknown side. Check Your Work: Use the Pythagorean theorem to verify: a² + b² = c² This systematic approach works for any right triangle problem where you know one angle and one side. Practice with different angles and given sides to build confidence!

This is the written version of the interactive lesson above. See the full Trigonometry course.