Question

In a triangle ABC, angle A +angleB=120°,angleC+angleA =140°,find angle A​

Answer 1

Answer:

IN ΔABC :

∠A + ∠B + ∠C = 180°   -----(1)

∠A + ∠B = 120°   -----(2)

FROM EQN. (1) AND (2):

120° + ∠C = 180°

∠C = 180° - 120°

∠C = 60°

∠A + ∠C = 140°

∠A = 140° - 60°

∠A = 80°

∠A + ∠B = 120°

∠B = 120° - 80°

∠B = 40°

HENCE ; ∠A = 80°   ∠B = 40°   ∠C = 60°

PLS MARK THIS AS BRAINLIEST

Answer 2

Step-by-step explanation:

<A + <B = 120° ------(1)

<A + <C = 140° ------(2)

But,

<A + <B + <C = 180° ------(3)

From (1) and (3)

120 + <C = 180°

<C =60°

From (2) and (3)

<B + 140° = 180°

<B = 40°

Substituting the values of <B and <C in eq. (3), we get

<A + 40° + 60° = 180°

<A = 80°