1. Honors Geometry Sections 10.1 & 10.2 part 2 Solving Right Triangles

2. To solve a right triangle means to determine the measures of all six parts. On our last page of notes, we used trigonometry to find side lengths when given the acute angle measures. Today, we’ll learn to find the acute angle measures given the side lengths.

3. Examples: Give the trig ratios for the triangle below. sin A = tan B = In the same way that division cancels out multiplication or the square root cancels out a square, the arcsine (sin -1 ) will cancel out sine, arctangent (tan -1 ) will cancel out tangent and arccosine (cos -1 ) will cancel out cosine.

4. These arc functions are usually found written above the sin, cos and tan buttons on the calculator. You usually must press the 2 nd button (or the INV button) to use these functions.

5. Solve each triangle. Round answers to three decimal places.

8. Example: The support wires for a cell phone tower are attached at a point 100 feet up the tower and anchored in the ground 75 feet from the bottom of the tower. Find the length of the support wires and the angle formed by the support wire and the ground. Round to the nearest 1000 th. 100 75 c x