Two intersecting lines create four angles with the same vertex, labeled A, B, C, and D. Angle B is adjacent to ∠A and ∠C. Find m∠A if m∠C=75°.(1 point)

Responses

75°
75 degrees

105°
  105 degrees

15°
  15 degrees

180°

We know that angle B is adjacent to angles A and C, meaning that angle A and angle C share a side with angle B. Since the sum of the angles in a triangle is 180 degrees, we can determine that angle B + angle A + angle C = 180.

Since we are given that angle C = 75 degrees, we can substitute this value into the equation.

angle B + angle A + 75 = 180

We can subtract 75 from both sides to isolate angle B and angle A.

angle B + angle A = 105

Since angle B and angle A share a side with angle C, we can conclude that they must be equal. So angle B = angle A.

Substituting angle A with angle B, we get:

2angle B = 105

Dividing both sides by 2, we find that angle B = 52.5 degrees.

Since angle A is equal to angle B, angle A also equals 52.5 degrees.