find the volume of cone, if its total surface area is 7128 sq. cm. and radius of base is 28cm. (π=22/7).
plz hlp argent
Attachments:
Answers
Answered by
5
Given: Radius (r) = 28 cm,
Total surface area of cone = 7128 sq.cm
To find: Volume of the cone
i. Total surface area of cone = πr (l + r)
∴ 7128= y x 28 x (l + 28)
∴ 7128 = 22 x 4 x(l +28)
∴ l + 28 = 7128/22 x 4
∴ l + 28 = 81
∴ l = 81 – 28
∴ l = 53 cm
ii. Now, l2 = r2 + h2
∴ 532 = 282 + h2
∴ 2809 = 784 + h2
∴ 2809 – 784 = h2
∴ h2 = 2025
∴ h = √2025 …
[Taking square root on both sides] = 45 cm = 22 x 4 x 28 x 15 = 36960 cm³
valume of cube = 36960cm³
Similar questions