The volume of a cone is 9856 cu cm. If the diameter of its base is 28 cm, what is its height and its slant height?
We have

Given: diameter of the base of the cone = 28 cm
⇒ radius, r = 28/2 = 14 cm
Volume of the cone = 9856 cm3
We know,
Volume of cone = 1/3 πr2h
⇒ 
⇒ 
⇒ 
⇒ 
So, we have r = 14 cm and h = 48 cm. In right-angled ∆COB, using Pythagoras theorem
CB2 = OB2 + CO2
⇒ l2 = r2 + h2, where l = slant height
⇒ l2 = 142 + 482
⇒ l2 = 196 + 2304 = 2500
⇒ l = √2500 = 50
Thus, height is 48 cm and slant height is 50 cm.