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

Question 5

Step 1: Find the side length of one regular hexagon.

A regular hexagon has 6 equal sides.

Perimeter of one hexagon = 30 cm.

So, side length = (30 div 6 = 5) cm.

Step 2: Add the perimeters before joining.

Two hexagons (separately) would have total perimeter = (30 + 30 = 60) cm.

Step 3: Understand what happens when they are joined.

When the hexagons are joined along one full side, that shared side is no longer on the outside.

We had counted that side once in the first hexagon and once in the second hexagon.

So, we must remove both of those outer counts.

Step 4: Subtract the two shared sides.

Length of one side = (5) cm.

Two such sides together = (2 imes 5 = 10) cm.

New perimeter = (60 - 10 = 50) cm.

Answer: (50) cm (Option D).