Question

Question 8 options:
Below, l1∥l2, with transversal lines m and n.

Find the values of A and B.



A =

B =

Answer 1

Answer:

• A = 105°
• B = 50°

Step-by-step explanation:

Call the angle immediately CCW from B (below line l2) angle C. Then angle C is corresponding with the one marked 55°, so is 55°. Angle B+C is supplementary to the one marked 75°, so is 105° Then ...

  angle B = (B+C) - C = 105°-55° = 50°

Angle A is an alternate exterior angle to angle (B+C), so is congruent to it. That means ...

  angle A = angle (B+C) = 105°