Question

find the unknown angle
how to solve this problem??
​

Answer 1

a)Find x and y

BCD=ACB+ACD

180°=ACB+150°

ACB=180°-150°

ACB=30°

since triangle ABC is an isosceles triangle

therefore, AB=BC

BAC=ACB

y=ACB=30°

ACB+ABC+BAC=180°

ABC+2BAC=180°

ABC+2*30°=180°

ABC=180°-60°

ABC=120°

X=120°