It is known that BK is the bisector of the angle ABC. Find the angle ABC if the angle ABC is 20 degrees greater than the angle ABK.

1. Let the degree measure of the angle ABK be x.

2. Determine the degree measure of the angle ABC:

(x + 20˚).

3. Since VK is the bisector of angle ABC, angle ABC = 2 * angle ABC.

Let’s compose and solve the equation:

2x = x + 20˚;

2x – x = 20˚;

x = 20˚.

4. The degree measure of the AВK angle is x = 20˚.

5. What is the degree measure of the angle ABC?

x + 20˚ = 20˚ + 20˚ = 40˚.

Answer: the degree measure of the angle ABC is 40˚.