NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 2: Geometry - Fill in the Blanks

Question 25

Think: A straight angle looks like a straight line.

1. By definition:
   \(\text{Straight angle} = 180^\circ\).

2. In the figure, points A–O–C lie on one straight line.
   So, \(\angle AOC = 180^\circ\).
   Hence, \(\angle AOC\) is a straight angle.

3. Points B–O–D lie on another straight line.
   So, \(\angle BOD = 180^\circ\).
   Hence, \(\angle BOD\) is a straight angle.

4. Counting straight angles:
   \(\angle AOC\) and \(\angle BOD\) → total \(2\).