ICSE Board Question Based on Mensuration Chapter of M.L Aggarwal for class10
In this question width,diameter and slant height of a conical tent is given.
Also find the cost of the canvas at the rate of Rs 80 per metre.
This is the Question Number 14, Exercise 17.2 of M.L Aggarwal.
Deepak BoraNewbie
Find what length of canvas 2 m in width is required to make a conical tent 20 m in diameter and 42 m in slant height allowing 10% for folds and the stitching. Also find the cost of the canvas at the rate of Rs 80 per metre.
Share
Given diameter of the conical tent, d = 20 m
radius, r = d/2 = 20/2 = 10 m
Slant height, l = 42 m
Curved surface area of the conical tent = πrl
= (22/7)×10×42
= 22×10×6
= 1320 m2
So the area of canvas required is 1320 m2.
Since 10% of this area is used for folds and stitches, actual cloth needed = 1320+ 10% of 1320
= 1320 + (10/100)×1320
= 1320+132
= 1452 m2
Width of the cloth = 2m
Length of the cloth = Area/width = 1452/2 = 726 m
Cost of canvas = Rs.80 per metre.
Total cost = 80×726 = Rs. 58080
Hence the total cost of the canvas is Rs. 58080.