Question

What are the measures of angles B and C

Answer 1

In a parallelogram opposite angles are equivalent so B=D and A=C.

If B=D, 3n + 20 = 6n - 25; add 25 to both sides

3n + 45 = 6n; subtract 3n from both sides

45 = 3n; divide both sides by 3

15 = n; substitute 15 for n to find the value of angle B;

3(15) + 20 = B

45 + 20 = B

65° = B

Angles C and B are supplementary, which means that when added they equal 180°

so 180 = 65 + C

115 = C

Your answer is choice B