Question

refer to right triangle ABC with C = 90degrees. Given a= 2 and b=√5 Find the six trigonometric functions of A. and find the angles A and B

Answer 1

In terms of angle A, the adjacent is √5, the opposite is 2, and the hypotenuse is 3

so
sinA = opposite/hypotenuse = 2/3
etc.
(you should definitely know the definitions of the trig ratios)

for angle A
sin^-1 (2/3) = 41.8°
B = 90-A = .....