Question

In triangle ABC. if ∠A + ∠B = 120⁰ and ∠B + ∠C = 100⁰ then find value of ∠B-
don't write unnecessary​

Answer 1

Step-by-step explanation:

In triangle ABC ,

<A + <B + <C = 180....measure of triangle

120° + <C = 180°

<C = 180° - 120°

<C = 60°_____(1)

then similarly,

<A + <B +<C = 180°

< A + 100° = 180°

< A = 80°______(2)

Now,

< A + <B + < C = 180°

80° + <B + 60° = 180°

< B = 180°- 60° -80°

<B = 40°

hence the measure of Angle B is 40°