Computer Graphics Through OpenGL, 2nd Edition

Appendix C

Math Self-Test Solutions

Score 4 points for each correct answer. For an assessment of your total, read the part before the start of the test.

Use the following if you need to (some are approximations): sin 30° = cos 60° = 0.5, sin 45° = cos 45° = 0.707, sin 60° = cos 30° = 0.866, π = 3.141, √2 = 1.414, √3 = 1.732.

The first seven questions refer to Figure C.1(a).

Figure C.1:

(a) Circle of unit radius (b) Right-angled triangle (c) Two circles of unit radius.

1. What is the equation of the circle?

   Answer: Generally, the equation of a circle on the xy-plane centered at (a, b) and of radius r is

   ${(x−a)}^2+{(y−b)}^2$