PLEASE HELP ILL GIVE YOU BRAINLIST PLEASE

55°

Step by step:

80 + x = 180

x = 100

Because the bottom of the figure is a line which equals 180°, so you would subtract 80 from 180 to get the angle on the other side of the line dividing the triangles.

Then, you would use the triangle sum theory which states that the angles of a triangle equals to 180.

100 + 25 + x = 180

125 + x = 180

x = 55°

So angle CBD = 55°

The answer is part a: use