Question

What are a, b, c and d​

Answer 1

Explanation:

4 g.

c=42

a=b=d

a+b+42=180

a+a=180-42

2a=138

a=138/2=69

a=69

b=69

c=42

d=69

5a.

a=30

angle O=180-(a+30)=180-(30+30)=180-60=120°

d=80

angle O=180-(d+80))=180-(80+80)=180-160=20°

central angle O of middle triangle=180-(120+20)=180-140=40°

b=c

b+c+40=180

b+b=180-40

2b=140

b=140/2=70

b=70°

c=70°