∴The angle between the height of the cone and aradius of the base is a right angle.
The measure of the space occupied by any cone iscalled volume of the Cone.
Volume of a Cone =1/3 x area of base x height.
Base of a Cone is a circle.What is the area of a circle?a) πr2b) 2πrc) πd
Area of base = πr2∴ volume of a cone = 1/3 xπr2x h= 1/3 πr2h
1. The height of a cone is 14cm and the radius of its base is3cm. What is its volume?Solution : Here, r= 3cm, h= 14cmVolume of cone = 1/3πr2h= 1/3x 22/7 x 3x3 x14= 22x 3 x9= 132 cu.cm
2. Find the volume of a cone of height 7cm and a base radiusof 9cm.Solution: Here, r = 9cm , h = 7cmVolume of Cone = 1/3πr2h= 1/3 x 22/7 x 9 x 9 x 7= 22 x 3 x9= 594 cu. cm
3.The radius of the base of a cone is 5cm and it’s slantheight is 13cm. Find the volume of thecone.(π=3.14)Solution: here r=5cm, l=13cmTo find out the volume of the cone we require height(h)of the cone.
The height and the radius of a cone form a rightangle.So we will use ‘Pythagoras’ theorem to find out heheight of the cone.