Write an equation for the line gragh

What number should be added to both sides of the equation to complete this square? x^2-10x=7

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)?

What is the distance between point a and b