1) pi/4 = 45°, 2pi/3 = 120°, 11pi/3 = -60° = 300°, -pi/2 = -90° = 270°,
10pi = 0 = 360°, 4 радиана ≈ 4*(57° 17') = 229° 8' = 130° 52'
2) t1 = 0, sin t2 = 1/2, t2 = 30° = pi/6
cos t3 = 1/2, t3 = -60° = 300° = -pi/3 = 11pi/3
t4 = 180° + 45° = 225° = -135° = 5pi/4 = -3pi/4