Maths Crash Course - Live lectures + all videos + Real time Doubt solving!

Chapter 13 Class 10 Surface Areas and Volumes

Serial order wise

Last updated at July 18, 2019 by Teachoo

Maths Crash Course - Live lectures + all videos + Real time Doubt solving!

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 πβ(π12+π22+π1π2) Hence , h = height of frustum = 14 cm r1 = (π·πππππ‘ππ ππ 1^π π‘ πππ)/2 = 4/2 = 2 cm r2 = (π·πππππ‘ππ ππ 2^ππ πππ)/2 = 2/2 = 1 cm Volume of glass = 1/3 πβ(π12+π22+π1π2) = 1/3Γ22/7Γ14(22+12+2Γ1) = 1/3 Γ 22Γ2(4+1+2) = (22 Γ 2 Γ 7)/3 = 308/3 = 102.66 cm3 Hence, volume of glass = 102.66 cm3