Base perimeter of a cone is 40π cm, height is 15cm. find TSA
Answers
Answered by
0
Step-by-step explanation:
Base of a cone is in the shape of a circle
& Perimeter of base of cone i.e. circle = 40pi cm
=> 2×pi×r = 40×pi cm
(pi gets cancelled as it is present on both sides)
=> 2r = 40 cm
=> r = 20cm
h = 15cm
l(slant height) = root[(r)^2+(h)^2]
= root[(20)^2 + (15)^2]
= root(400+225)
= root625
= 25cm
T.S.A. of cone = pi×r(r+l)
=pi × 20(20+25)
=pi × 20 × 45
= 900pi cm^2
We can also put the value of pi=22/7
Therefore,T.S.A. = 900×22/7 cm^2
= 19800/7 cm^2
Similar questions