NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 2: Geometry - Multiple Choice Questions
Question 9

Question. 9

The number of obtuse angles in Fig. 2.9 is

(A)

2

(B)

3

(C)

4

(D)

5

Detailed Answer with Explanation:

Goal: count obtuse angles.

Step 1: Meaning of an obtuse angle.

\(90^\circ < \theta < 180^\circ\)

Step 2: Read the marked angles in the figure.

\(115^\circ\)
\(135^\circ\)
\(155^\circ\) (approx.)

Step 3: Check each value against the rule.

\(90^\circ < 115^\circ < 180^\circ\)
\(90^\circ < 135^\circ < 180^\circ\)
\(90^\circ < 155^\circ < 180^\circ\)

All three are obtuse. Count \(= 3\). Answer: option B.

NCERT Exemplar Solutions Class 6 – Mathematics – Unit 2: Geometry – Multiple Choice Questions | Detailed Answers