Advertisements
Advertisements
Question
The cost of levelling the ground in the form of a triangle having the sides 51 m, 37 m and 20 m at the rate of Rs 3 per m2 is Rs 918.
Options
True
False
Advertisements
Solution
This statement is True.
Explanation:
a = 51, b = 37, c = 20
`s = (a + b + c)/2`
⇒ `s = (51 + 37 + 20)/2 = 108/2 = 54`.
Area (Δ) = `sqrt(s(s - a)(s - b)(s - c))`
⇒ Area (Δ) = `sqrt(54(54 - 51)(54 - 37)(54 - 20))`
⇒ Area (Δ) = `sqrt(54 xx 3 xx 17 xx 34)`
⇒ Area (Δ) = 306 m2
Cost of painting = Area (Δ) × Cost per m2
⇒ Cost of painting = 306 × 3 = Rs. 918
APPEARS IN
RELATED QUESTIONS
A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?
An isosceles triangle has perimeter 30 cm and each of the equal sides is 12 cm. Find the area of the triangle.
The adjacent sides of a parallelogram ABCD measure 34 cm and 20 cm, and the diagonal AC measures 42 cm. Find the area of the parallelogram.
Find the area of the triangle formed by the points
(–10, –4), (–8, –1) and (–3, –5)
Find the area of triangle FED
The area of a triangle is 5 sq. units. Two of its vertices are (2, 1) and (3, −2). The third vertex is (x, y) where y = x + 3. Find the coordinates of the third vertex.
Find the area of the unshaded region
If the side of a rhombus is 10 cm and one diagonal is 16 cm, the area of the rhombus is 96 cm2.
The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 13 m, 14 m and 15 m. The advertisements yield an earning of Rs 2000 per m2 a year. A company hired one of its walls for 6 months. How much rent did it pay?
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.
