I really need help pls. Its about 3d shapes

Cot(90° − x) = 1 the value of x that satisfies this equation is °. a. 60 b. 135 c. 225 d. 315

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Apiling for a high-rise building is pushed by two bulldozers at exactly the same time. one bulldozer exerts a force of 1250 pounds in a westerly direction. the other bulldozer pushes the piling with a force of 2650 pounds in a northerly direction. what is the direction of the resulting force upon the piling, to the nearest degree? a. 65 n of w b. 25 n of w c. 45 n of w d. 35 n of w