Last updated at July 18, 2019 by Teachoo

Transcript

Ex 13.4, 1 A drinking glass is in the shape of a frustum of a cone of height 14 cm. The diameters of its two circular ends are 4 cm and 2 cm. Find the capacity of the glass. Since glass is in from of frustum Capacity of glass = Volume of frustum = 1/3 ๐โ(๐12+๐22+๐1๐2) Hence , h = height of frustum = 14 cm r1 = (๐ท๐๐๐๐๐ก๐๐ ๐๐ 1^๐ ๐ก ๐๐๐)/2 = 4/2 = 2 cm r2 = (๐ท๐๐๐๐๐ก๐๐ ๐๐ 2^๐๐ ๐๐๐)/2 = 2/2 = 1 cm Volume of glass = 1/3 ๐โ(๐12+๐22+๐1๐2) = 1/3ร22/7ร14(22+12+2ร1) = 1/3 ร 22ร2(4+1+2) = (22 ร 2 ร 7)/3 = 308/3 = 102.66 cm3 Hence, volume of glass = 102.66 cm3

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.