Trigonometry is used to determine the measures (sides and angles) of a right triangle. The document reviews three trigonometric functions: sine, cosine, and tangent. Sine relates an angle to the opposite side over the hypotenuse. Cosine relates an angle to the adjacent side over the hypotenuse. Tangent relates an angle to the opposite side over the adjacent side. An example problem is shown to find missing sides and angles of a right triangle when given one angle measure and the side opposite to it.