Question

If height and radius of cone are h and r respectively and it's given that height of the cone is same as diameter of the base then find its slant height

Answer 1

h=d
h=2r
By Pythagoras Theorem,
$l^{2}=h^{2} + r^{2}$
l=sqrt {(2r)^2+r^2}
l=sqrt {4(r)^2+(r)^2}
l=sqrt {5 (r)^2}
$l = \sqrt{5 {r}^{2} }$

Answer 2

Answer : Since it is given that Height = Diameter

. Height= 2 Radius

h=2r ..........(1)

We know that

(slant height) ²= height² + Radius ²

l²=r² + h²

From equation (1) ,

l²=r² + (2r)² + r²

l²=r² + 4r²

l²=5r²

l=√5 r