Is 9x-(9x)^2=19-y linear or non linear

1) in triangle the, what is the measure of angle t (in degrees)? 2) in triangle bat, the measure of angle b is 66∘, and the measure of angle t is 77∘.what is the measure of the exterior angle at a (in degrees)?

Which of the following is the shape of a cross section of the figure shown below

What ia the sum if the first 7 terms of the geometric series