Question

I need help on the Wednesday column, question 1, letter b.

Answer 1

AREA RELATED TO CIRCLES

Area of grass border = Area of bigger circle - area of smaller circle

$Area \: of\: grass \: border \: = \:\pi {R}^{2} - \pi {r}^{2}$

$Area \: of \: grass \: border \: = \: \pi( {R}^{2} - {r}^{2} )$

$Area \: of\: grass \: border\: = \: \pi(R + r)(R - r) \\\\\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:= \: \:\frac{22}{7} (4 + 3)(4 - 3) \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:= \frac{22}{7} \times 7 \times 1 \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:= 22 \: \: {m}^{2} \: \: \: \: \: \: Ans.$

Answer 2

Multiply 4 and 4.

4 x 4 = 16

Multiply 3.14 and 16.

3.14 x 16 = 50.24

Subtract 28.26 from 50.24.

50.24 - 28.26 = 21.98

Answer for Letter B = 21.98 m

Hope this helped!