Question

Solve for the value of r.
(6r-7)
55°

Answer 1

r=7

Explanation:

6r-7+90+55=180

6r+138=180 ----- 6r=180-138

6r=42 ----- divide both sides by 6

r=7

(We get the 90 from the 90degrees in the middle of this supplementary angle and the total, 180, from the straight angle made from all three angles.)

hope this helps!