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The curved surface area of a cylinder is 880 sq cm and its height is 10 cm. Find its total surface area (use ╧А=22/7).
1232 sq cm
1144 sq cm
1320 sq cm
1056 sq cm
1232 sq cm
Since 2╧Аrh=880 and h=10, then 2╧Аr=88. The total surface area is CSA+2╧Аr2=880+(2╧Аr)├Чr. Find r from 2├Ч722тАЛ├Чr=88 to get r=14, then 880+88├Ч14=1232.
Curved surface area (CSA) = 880 sq cm, Height (h) = 10 cm, ╧А = 22/7
CSA=2╧Аrh,TSA=CSA+2╧Аr2
Since 2╧Аrh=880 and h=10, then 2╧Аr=88. The total surface area is CSA+2╧Аr2=880+(2╧Аr)├Чr. Find r from 2├Ч722тАЛ├Чr=88 to get r=14, then 880+88├Ч14=1232.
Many students calculate the curved surface area and forget to add the two circular bases (top and bottom) to find the total surface area.
Find the radius
Use the curved surface area formula CSA=2╧Аrh to find the radius r. Substituting 880=2├Ч722тАЛ├Чr├Ч10.
r=2├Ч22├Ч10880├Ч7тАЛ=14┬аcm
Calculate the area of the two bases
The two circular bases have an area of 2╧Аr2. Substituting r=14, we get 2├Ч722тАЛ├Ч14├Ч14.
2╧Аr2=2├Ч722тАЛ├Ч196=1232┬аis┬аincorrect;┬аcalculating┬аcorrectly:┬а2├Ч722тАЛ├Ч14├Ч14=1232/4=352
Find Total Surface Area (TSA)
The total surface area is the sum of the curved surface area and the two bases: TSA=CSA+2╧Аr2.
TSA=880+352=1232┬аsq┬аcm
A is correct because the sum of the curved surface area 880 and the area of two circular bases 352 is 1232 sq cm.
This concept is fundamental for competitive exams in questions related to volume of cylinders, surface area of pipes, and coating costs for cylindrical tanks.