Advertisements
Advertisements
Question
The sides of the triangular ground are 22 m, 120 m and 122 m. Find the area and cost of levelling the ground at the rate of ₹ 20 per m2
Advertisements
Solution
The sides of the triangular ground are 22 m, 120 m and 122 m
a = 22 m, b = 120 m, c = 122 m
s = `("a" + "b" + "c")/2`
`(22 + 120 + 122)/2 "m"`
= 132
s – a = 132 – 22 = 110 m
s – b = 132 – 120 = 12 m
s – c = 132 – 122 = 10 m
= `sqrt("s"("s" - "a")("s" - "b")("s" - "c"))`
= `sqrt(132 xx 110 xx 12 xx 10)`
= `sqrt(2^2 xx 3 xx 11 xx 11 xx 10 xx 2^2 xx 3 xx 10)`
= `sqrt(2^4 xx 3^2 xx 10^2 xx 11^2)`
= 4 × 3 × 10 × 11
= 1320 sq.m
Cost of levelling for one sq.m = ₹ 20
Cost of levelling the ground = ₹ 1320 × 20
= ₹ 26400
Area of the ground = ₹ 1320 sq.m
Cost of levelling the ground = ₹ 26400
APPEARS IN
RELATED QUESTIONS
The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 122m, 22m, and 120m (see the given figure). The advertisements yield an earning of ₹ 5000 per m2 per year. A company hired one of its walls for 3 months. How much rent did it pay?

The perimeter of a triangle is 300 m. If its sides are in the ratio 3 : 5 : 7. Find the area of the triangle ?
A rhombus sheet, whose perimeter is 32 m and whose one diagonal is 10 m long, is painted on both sides at the rate of Rs 5 per m2. Find the cost of painting.
Determine whether the sets of points are collinear?
(a, b + c), (b, c + a) and (c, a + b)
Using Heron’s formula, find the area of a triangle whose sides are 1.8 m, 8 m, 8.2 m
An advertisement board is in the form of an isosceles triangle with perimeter 36 m and each of the equal sides are 13 m. Find the cost of painting it at ₹ 17.50 per square metre.
A field in the form of a parallelogram has sides 60 m and 40 m and one of its diagonals is 80 m long. Find the area of the parallelogram.
The sides of a quadrilateral ABCD are 6 cm, 8 cm, 12 cm and 14 cm (taken in order) respectively, and the angle between the first two sides is a right angle. Find its area.
A rhombus shaped sheet with perimeter 40 cm and one diagonal 12 cm, is painted on both sides at the rate of Rs 5 per m2. Find the cost of painting.
In the following figure, ∆ABC has sides AB = 7.5 cm, AC = 6.5 cm and BC = 7 cm. On base BC a parallelogram DBCE of same area as that of ∆ABC is constructed. Find the height DF of the parallelogram.

