Can you tell me if i'm right and also, what is the opposite of -12

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

What is the 12th term of b(n)=-4-2(n-1)

Carmen begins her next painting on a rectangular canvas that is 82.7 cm long and has a area of 8,137.68 cm2. will the painting fit in a frame with an opening that is 82.7 cm long and 95 cm wide? explain