Given:
m∠C = 70°
m∠CDE = 130°
Question 1:
To find ∠CDB, let's use the exterior angle theorem.
The exterior angle theorem states that the sum of 2 opposite interior angles is equal to the exterior angle.
Thus,
m∠C + m∠B = 130
70 + m∠B = 130
Subtract 70 from both sides:
70 - 70 + m∠B = 130 -70
m∠B = 60°
Now, use the triangle angle sum theorem to find ∠CDB.
The triangle angle sum theorem states that the sum of interior angles in a triangle is 180°
∠CDB = 180 - 70 - 60 = 50°
∠CDB = 50°
Question 2:
∠CBA = ∠C + ∠CDB
∠CBA = 70 + 50 = 120°
∠CBA = 120°
ANSWER:
∠CDB = 50°
∠CBA = 120°