Q11 of 51 Page 13

A cone of radius 10 cm is divided into two parts by drawing a plane through the midpoint of its axis, parallel to its base. Compare the volume of the two parts.

Volume of a cone: volume of frustum = 1:7

Given: The figure is shown below



Explanation:


Radius of cone, r = 10cm


From the figure, we can see that the cone is divided into two equal parts by the axis. So,


In


∠PAC = ∠QAD (common)


∠AQD = ∠APC = 90°


So, ∆AQD~∆APC ( by AA-similarity)



So, radius,


Now, the volume of frustum =





Comparing the volume of the frustum and the cone



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