Question

the inner diameter of circular well is 3.5 m it is 10m deep find inner CSA

Answer 1

Radius is 1.75 m
Height is 10m
Curved Surface Area =2*22/7*1.75*10
= 110m2
Cost of plastering = 110*40
=Rs. 4400

Answer 2

Answer:

Inner radius of circular well -

$\\ \sf \bigg( \frac{3.5}{2} \bigg) \: m = 1.75 \: m$

• Height of circular well = 10 m
• inner curved surface area = 2πrh

$\\ \implies \sf \: \bigg(2 \times \frac{22}{ 7} \times 1.75 \times 10 \bigg) \: \: m {}^{2} \\ \\ \\ \implies \sf \: (44 \times 0.25 \times 10) \: \: {m}^{2} \\ \\ \\ \implies \sf \: 110 \: \: {m}^{2}$

Therefore, the inner curved surface area of circular well is 110 m².

• Cost of plastering 100 m² area :

$\\ \implies \sf \: rs. \: (110 \times 40) \\ \\ \\ \implies \sf \: rs.4400$