Question

ABCDE is the end view of a factory shed which is 50 m long. The roofing of the shed consists of asbestos sheets as shown in the figure. The two ends of the shed are completely closed by brick walls.

If the cost of asbestos sheet roofing is Rs. 20 per m², find the cost of roofing.

Answer 1

Asbestos sheets are spread on the area formed by the rectangle with CD and DE as lengths.
In ΔCDE, by Pythagoras theorem,
DE² = `("perpendicular")^2 + ("Ab"/2)^2`

DE2 = `3^2 + (8/2)^2`
DE² = 3² + 4²
DE² = 25
∴ DE = CD = 5m
Area of asbestos sheets = DE x length + Dc x length
Area of asbestos sheet
= 2 x 5 x 50
= 500m²
Cost of roofing
= Area x rate
= 500 x 20
= Rs.10,000
∴ The cost of roofing is Rs.10,000.