A semi-circular sheet of metal of diameter 28 cm is bent to form an open conical cup. Find the capacity of the cup.
Given: Diameter of semi circular sheet = 28cm
To find: Volume/ Capacity of open conical cup
Semi Circular sheet is bent to form an open conical cup
Thus, slant height of a conical cup (l)=radius of semicircular sheet
(r) = 14cm
We know that, Circumference of base of a cone = 2πR
Where, R = radius of a cone
Circumference of semi circle = πr
Thus, Circumference of base of a cone = Circumference of a
Semi circle
⇒ 2πR= πr
Thus, to find height of a cone we will use a formula
R2 + h2 = l2 where R=radius of a cone
h=height of a cone
l=slant height of a cone
⇒ (7)2 + h2 = (14)2
⇒ 49+ h2 = 196
⇒ h2 = 196 – 49 = 147
⇒ h = √147 = 7√3 cm
Thus, 
Where, 
R = radius of a cone
h = height of a cone
Thus, 
