The radius and height of a cylinder are in the ratio 7:2. If the volume of the cylinder is 8316 cm3. Find the total surface area of the cylinder.
Let r,h be radius & hight of cylinder
⇒volume=πr2h,Total surface area (T.S.A)=2πr(h+r)
Given. rh=72⇒h=2r7
Volume =πr2h=8316⇒πr2(2r7)=8316
⇒r3=8316×7×72×22=73×11882×22=73×33
⇒r=7×3=21cm⇒h=27×21=6cm
T.S.A=2πr=(h+r)=2×227×21(6+21)=44×3×27
=3564cm2