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# A dinner plate is in the form of a circle. A circular region encloses a beautiful design as shown in Fig. 9.70. The inner circumference is 352 mm and outer is 396 mm. Find the width of circular design.

**Solution:**

Given, a dinner plate is in the form of a circle.

A circular region encloses a beautiful design.

The inner circumference is 352 mm and the outer is 396 mm.

We have to find the width of the circular design.

__Circumference__ = 2πr

Outer circumference = 2πR

396 = 2(22/7)R

396 = (44/7)R

R = 396(7)/44

R = 9(7)

R = 63 mm

Inner circumference = 2πr

352 = 2(22/7)r

352 = (44/7)r

r = 352(7)/44

r = 8(7)

r = 56 mm

Width of circular ring = R - r

= 63 - 56

= 7 mm

Therefore, the width of the design is 7 mm.

**✦ Try This: **A dinner plate is in the form of a circle. A circular region encloses a beautiful design. The inner circumference is 400 mm and outer is 600 mm. Find the width of circular design.

**☛ Also Check: **NCERT Solutions for Class 7 Maths Chapter 11

**NCERT Exemplar Class 7 Maths Chapter 9 Problem 129**

## A dinner plate is in the form of a circle. A circular region encloses a beautiful design as shown in Fig. 9.70. The inner circumference is 352 mm and outer is 396 mm. Find the width of circular design.

**Summary:**

A dinner plate is in the form of a circle. A circular region encloses a beautiful design as shown in Fig. 9.70. The inner circumference is 352 mm and outer is 396 mm. The width of the circular design is 7 mm.

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