1.

In ΔABC, AB = AC, ∠C = x  and the angle A = (5x - 30)°: find the angle B (in degrees).1. 30° 2. 60° 3. 80° 4. 120°

Answer» Correct Answer - Option 1 : 30° 

Given:

In ΔABC, AB = AC

∠A = (5x – 30)° 

∠C = x

Concept used:

If two sides of a triangle are equal their opposite angles will also be equal.

The sum of all angles of a triangle is 180∘ .

Calculation:

AB = AC

⇒ ∠C = ∠B = x

According to question,

5x – 30° + x + x = 180° 

⇒ 7x – 30° = 180° 

⇒ 7x = 210° 

⇒ x = 30° 

∴ The value of ∠B is 30° 



Discussion

No Comment Found

Related InterviewSolutions