Pls answer this geometry question 100% smart people

Evaluate cos2θ for cosθ = square root of 3/2

Pls as soon as ! will award brainliest and 20 ! also the answer is not 22.5 degrees! find the value of x in each case:

The first triangle is dilated to form the second triangle. select true or false for each statement. statement true false the scale factor is 0.625. the scale factor is 1.6. a right triangle with a side length of .5. an arrow points to a larger right triangle with a side length of .8