What are the characteristics of the triangle? What kind of triangle has these?
This is an isosceles right triangle because 2 side lengths are equal and 2 sides a perpendicular.
What trigonometric ratio can you use to find the measure of the angle?
Refer to the Math Notes Box in Lesson 5.1.2 for the trigonometry ratios and don't forget about inverse trigonometry.
Use the eTool below to visualize the problem and answer questions (a) and (b).
Click the link at right for the full version of the eTool: GC 8-16 HW eTool