The point p (3,4) is the midpoint of the join of A (7,8) and B find the coordinates of B

In the first triangle 80+20+p=180 (since sum of all angles of a triangle is 180)so p= 80also in second triangle 55+45+q=180 (since sum of all angles of a triangle is 180)so q=80so we can conclude that p=80 degrees q=80 degrees so p=q=80 degreeshence option b is correct

For the first question the answer is a, for the second c, for the third d, for the 4th b, for the 5th a