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

Question 10

Step-by-step counting (very easy method)

1. Count the smallest triangles.
   Mark each tiny triangle once (do not double count). Suppose there are 9 such smallest triangles.
   \(\text{Small triangles} = 9\)
2. Make medium triangles by combining small ones.
   Look for triangles formed by joining small triangles together near each corner of the big figure. You will find 3 such medium triangles.
   \(\text{Medium triangles} = 3\)
3. Count the biggest triangle.
   The whole outer shape is 1 large triangle.
   \(\text{Large triangle} = 1\)
4. Add them.
   \(\text{Total} = 9\) + \(3\) + \(1\)
   \(= 13\)

Tip: Use a pencil to tick each triangle once to avoid repeating the same one.