Question

The sum of two angles of a triangle is 80° and their difference is 20°, then the smallest
angle
(A) 50°
(B) 60°
(C) 30°
(D) 20°
​

Answer 1

Answer:

50. option A

Step-by-step explanation:

hope that helps

Answer 2

Answer:

(C) 30°

Step-by-step explanation:

Given:

• sum of two angles of a triangle is 80

To find :

• the smallest angle

Solution :

Let the angles be

• ∠A and ∠B

Therefore,

∠A + ∠B = 80° ______(i)

∠A - ∠B = 20° ______(ii)

On addition equation (i) and (ii); we get;

∠A + ∠B = 80°

∠A - ∠B = 20°

____________

2∠A = 100°

∠A = 50°

On putting A = 50° on equation (i); we get;

∠A + ∠B = 80°

50° + ∠B = 80°

∠B = 80° - 50°

∠B = 30°

Therefore, the two angels are 50 and 30°

Sum of all angles of a triangle is 180°

∠A + ∠B + ∠C = 180°

50° + 30° + ∠C = 180°

80° + ∠C = 180°

∠C = 180° - 80°

∠C = 100°

Therefore, the smallest angle is 30°