Which theorem proves these triangles are similar?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.

The point a is at –2 and the point b is at 7. marissa would like to divide this line segment in a 4: 3 ratio, and she would like to use the formula x = (x2 – x1) + x1. what values should she substitute into the formula? a = a + b = x1 = x2 =