Question

Can someone help with number 20

Answer 1

Answer:B: 36°

Step-by-step explanation:

We know that ∆ABC is isoceles, making (angle)<ABC and <BCA congruent because base angles of isoceles triangles are congruent.

Because we have parallel lines, we can look for alternate interior angle pairs. <BCA is congruent to <DAC because they're alternate interior angles.

If <BCA is x then so is <ABC.

Since triangles add up to 180° we can add all of the angles (3x+x+x) and set it equal to 180.

3x+x+x=180

5x=180

x=36

If we were looking for <BAC we would plug that back in and solve, but we're looking for <BCA which is equal to x, therefore m<BCA=36°