Question

2. In a triangle ABC, if angle A- angle B = 42° and angle B-angle C = 21° then angle B = ?​

Answer 1

Answer:

B. In angle ABC ,

Angel A= 42°

Angel B = x

Angel C= 21°

Then one angel= 180°

Then we, 42° + 21° = 63

Then we subtract 63°from 180°

180°- 63°= 117°

Then, B = 117° Answer

Answer 2

Step-by-step explanation:

a+b+c=180°, a-b=42°-(1),b-c=21-(2)

now we add 1 and 2 and we get a-c=63

a=c+63,c=c,b=c+21

so, c+ 63+c+21+c=180°

3c=180-84=96

therefore, c=32,b=c+21=32+21=53°