Answer:
B) 81°
Step-by-step explanation:
Given:
From the figure given below,
∠1 = 3x + 18
∠7 = 2x + 39
∠1 and ∠7 are a pair of exterior alternate angles. For two parallel lines l and m, cut by a transversal n, the pair of exterior alternate angles are congruent to each other.
Therefore, the angles 1 and 7 are congruent to each other. This gives,
∠1 ≅ ∠7
Therefore, the value of 'x' is 21.
Now, the measure of angle 7 can be calculated by plugging in the value of 'x' in the expression for angle 7. This gives,
Therefore, the correct option is option (B).
