Question

the size of a rectangular field are in the ratio 5:3:4 and its perimeter is 180 m. Find 1. its area. 2. Altitude of the triangle corresponding to its large st side. 3. The cost of levelling the field at the rate of rupees 10 per square metre.

Answer 1

let length , breadth be in ratio 5x ,4x (m) resp.

so Area =length×breadth

3380 =5x × 4x

20x^2=3380

x^2=169

x=13

so length=5x=65m

breadth=4x=52m

perimeter=2(l+b)=2(65+52)=2× 117=234m

so the cost of fencing=75×234=Rs.17550