The value of ∠x is 135°.
Solution:
Given data:
m∠B = 69°, m∠C = 66° and ∠BAD = x
∠B and ∠C are interior angles of a triangle ABC.
∠BAD is an exterior angle of a triangle ABC.
Exterior angle of a triangle theorem:
An exterior angle of a triangle is equal to the sum of the opposite interior angles.
m∠BAD = m∠B + m∠C
∠x = 69° + 66°
∠x = 135°
The value of ∠x is 135°.
