Question

Find total surface area of cone with height 21m and base diameter 28m

Answer 1

Step-by-step explanation:

Answer:

2156 cm²

Explanation:

total surface area of a cone=πr(s+r)

where, radius is r, slant height is s.

since, diameter=28, then radius=14

s²=r²+h²

s=

\sqrt{ {14}^{2} + {21}^{2} }

14

2

+21

2

s=14+21

s=35

now,

area of cone=22/7×14(35+14)

=22×2×49

=22×98

=2156 cm²