Question

On the side of an 18 cm diameter plate, the design of 4 cm width in the interior is made, find out the area of ​​the design part.

Answer 1

Ra = 18/2 Rb = 9 - 4

Ra= 9 cm Rb = 5 cm

area of the design part = πRa² - π Rb²

= π9² - π5²

= π81 - π25

= π56 (put value π)

= (22/7) × 56

= 176 cm² Ans.

Answer 2

The area of ​​the design part. is 176 sq.cm.

Step-by-step explanation:

Diameter of plate = 18 cm

Radius of plate R = $\frac{18}{2}=9 cm$

We are given that the design of 4 cm width in the interior is made,

So, Inner radius r = 9 cm - 4 cm = 5 cm

Area of design = Outer area - inner area

Area of design =$\pi R^2 - \pi r^2$

Area of design =$\frac{22}{7}(9^2-5^2)=176 cm^2$

Hence  the area of ​​the design part. is 176 sq.cm.

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