Question

The area of the base of a cone is 616cm2, its height is 48cm, then the total surface area of cone is?

Answer 1

$<b><i>$

Area of circular base = 616 cm2


Therefore,
  
 πr2 = 616

⇒227r2  = 616

⇒r2  = 616 × 722

⇒r2  = 196

⇒ r = 14 cm

And h = 48 cm

Then slant height
l = r2+h2‾‾‾‾‾‾‾

√ = 142+482‾‾‾‾‾‾‾‾‾

√ = 196+2304‾‾‾‾‾‾‾‾‾‾‾

√ = 2500‾‾‾‾‾

√ = 50 cm

Total surface are of cone = πr(r+l) =
 227×14×(14 +50)

                                                        = 227×14 ×64= 2816 cm2