If cosx is approximately 0.9511, what is the measurement of x to the nearest degree? approximately, what is the sin of the angle that is complementary to x?

I used the calculator assigning various values of x to get 0.9511.

cos x = 0.9511 
cos 18° = 0.9511
sin and cos are complementary angles = 90° - 18° = 72°

sin 72° = 0.9511

sin 72° = cos 18