Question

If angle A=B and angle C=40 degree find A and B

Answer 1

Answer:

In a triangle ABC, sum of angles of a triangle are 180∘always.

∴∠ABC+∠BCA+∠CAB=180∘

Given : ∠CAB=55∘∠ABC=40°

∴55∘ +40∘+∠BCA=180°

∴∠BCA=180∘ −95∘

=85∘

we know ∠ABC=∠B,∠BCA=∠C and∠CAB=∠A

Answer 2

A -B = 40 .................................1

B -C = 10 ..................................2

Therefore , we get,

A - C = 50...........................5

Adding 2 and 5, we get,

2.........B - C = 10

5.........A - C = 10

=> A + B = 60..........................6

Adding 1 and 6 , we get,

1...............A - B = 40

6..............A + B = 60

Therefore ,

A = 100

Equating on eq. 1, we get,

A - B = 40

100 - B = 40

B = 60

Equating on eq.2 , we get,

B - C = 10

60 - C = 10

C= 50