Advertisements
Advertisements
प्रश्न
The perimeter of a triangle is 300 m. If its sides are in the ratio 3 : 5 : 7. Find the area of the triangle ?
Advertisements
उत्तर
Given that
The perimeter of a triangle = 300 m
The sides of a triangle in the ratio 3 : 5 : 7
Let 3x, 5x, 7x be the sides of the triangle
Perimeter ⇒ 2s = a + b + c
⇒ 3x + 5x + 17x = 300
⇒ 15x = 300
⇒ x = 20m
The triangle sides are a = 3x
= 3 (20)m = 60 m
b = 5x = 5(20) m = 100m
c = 7x = 140 m
semi perimeter s = `(a+b+c+)/2`
`=(300)/2m`
`=150m`
∴The area of the triangle `=sqrt(s(s-a)(s-b)(s-c))`
`=sqrt(150(150-60)(150-100)(150-140))`
`=sqrt(150xx10xx90xx50)`
`=sqrt(1500xx1500) 3 cm^2`
`∴Δ` le Area = 1500 `sqrt3 cm^2`
APPEARS IN
संबंधित प्रश्न
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?
The perimeter of a triangular field is 240 dm. If two of its sides are 78 dm and 50 dm, find the length of the perpendicular on the side of length 50 dm from the opposite vertex.
Sides of a triangle are cm 45 cm, 39 cm and 42 cm, find its area.
Look at the measures shown in the adjacent figure and find the area of ☐ PQRS.
Find the area of the triangle formed by the points
(1, – 1), (– 4, 6) and (– 3, – 5)
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
Find the area of an equilateral triangle whose perimeter is 180 cm
An isosceles right triangle has area 8 cm2. The length of its hypotenuse is ______.
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?
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.
