A heap of paddy is in the form of a right circular cone whose diameter is 4-2 m and height 2-8 m- If the heap is to be covered exactly by a canvas to protect it from rain- then the area of the canvas needed

Question

Toppr Admin · Accepted Answer

Required area of the canvas is equal to the curved surface area of the cone.

Given, diameter $= 4.2$ m

Thus, radius $= 2.1$ m

Also given, height $= 2.8$ m

Let $l$ be the salnt height of the cone

$l = \sqrt{h^{2} + r^{2}}$

$= \sqrt{{2.8}^{2} + {2.1}^{2}}$

$= \sqrt{7.84 + 4.41}$

$= \sqrt{12.25}$

$= 3.5$ m

Curved surface area of cone $= π r l$ square unit
$= \frac{22}{7} \times 2.1 \times 3.5$

$= 23.1 m^{2}$

Thus the required area of canvas is $23.1 m^{2}$

A heap of paddy is in the form of a right circular cone whose diameter is 4.2 m and height 2.8 m. If the heap is to be covered exactly by a canvas to protect it from rain, then find the area of the canvas needed

A heap of paddy is in the form of a right circular cone whose diameter is $4.2$ m and height $2.8$ m. If the heap is to be covered exactly by a canvas to protect it from rain, then find the area of the canvas needed