Question

what is the total surface area for solid cone 10cm radius and 8cm lenght? please show working out.

Answer 1

The lateral surface area of a cone: Area = πrs , where s is the slant height

and r is the radius of the base
Lateral area = π(10)(8) cm
= 80 cm, assuming that your 8 cm is the slant height
- if not, then use Pythagoras to find the slant height

Since you want the total surface area, we must also add the
area of the circular base, which would be π(10)^2 = 100π cm

Add them up and you are done