Question

solve the problem with full solution

Answer 1

We know that l² = h² + r²

so, r² = 13² -12² = 169 - 144

     r² = 25

 

so, Radius, r = 5 cm

Answer 2

For a cone, l2=r2+h2, where, l is the slant height, r is radius and h is perpendicular height.

Given,
 l=13cm,h=12cm

So, r=√132−122=5cm

Now, area of base of a cone is πr2 and area of lateral surface is πrl

So,total area is πr2+πrl

i.e πr(r+l)
=3.142×5×(5+13)
=282.78cm2