I is the incentre of $\triangle ABC$. If

CUET Preparation Today

Start Free Mocks

Home Questions T72VED7WQP

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Geometry

Question:

I is the incentre of $\triangle ABC$. If $\angle BIC = 108^\circ$, then $\angle A = ?$

Options:

54°

81°

72°

36°

Correct Answer:

36°

Explanation:

$\angle$BIC = 90 + $\angle$A/2

108 = 90 + $\angle$A/2

$\angle$A = 18 x 2 = ${36}^\circ$.

Therefore, $\angle$A is ${36}^\circ$.