Question

a heap of paddy is in the form of a cone whose radius is 2.1 and height is 2.8. if the heap is to be covered exactly by a canvas to protect it from rain, then find the area of canvas required

Answer 1

l²=h²+r²
l²=(2.8)²+(2.1)²
l²=12.25
l=√12.25
l=3.5
area of canvas = πr²l
       =22/7*(2.1)²*3.5
        =48.51 cubic units

Answer 2

slant heightof cone=. √h2+r2

√2.8*2.8+2.1*2.1= √12.25=3.5
area of canvas=. πrl
22*2.1*3.5/7=23.7 sq unit