Question

attached question, answerer(s) get medals!

Answer 1

a point is on a circle. the line tangent to the circle through that point and the radius of the circle to that point are perpendicular. so, 180-90-12=78.

Answer 2

The Value of x is 78

Answer 3

remember a triangles corners always equal 180.

Answer 4

oh, duh, of course. thanks!