Please... I really need to do this...
а) sin(2х + 3) = а + 4
б) 2cos(х + π/3) = а2 - 3а
в) tg22х - (2а +1)tg2х + а(а + 1) = 0.

If two angles of a triangle have equal measures and the third angle measures 90°, what are the angle measures of the triangle? a. 60°, 60°, 60° b. 45°, 90°, 90° c. 30°, 30°, 90° d. 45°, 45°, 90°