Answer:
Step-by-step explanation:
A fact to know: The measure of exterior angle of a triangle = the sum of the two remote interior angles.
So 120 = 22x + 4 + 15x + 5
120 = 37x + 9
111 = 37x
3 = x
m ∠B = 22 (3) + 4 = 70
m ∠C = 15(3) + 5 = 50
OR The exterior angle + m ∠CDB = 180 Definition of straight angle
So m ∠CDB = 60°
The sum of the angles in a triangle= 180
15x + 5 + 22x +4 + 60 = 180; 37x + 69 = 180; 37x = 111; x = 11
