A day full of math games & activities. Find one near you.

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?

Solution:

Given, 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.

We have to calculate the rent paid by the company for 6 months.

Let a = 13 m

b = 14 m

c = 15 m

By Heron’s formula,

Area of triangle = √s(s - a)(s - b)(s - c)

Where s = semiperimeter

s = (a + b + c)/2

So, s = (13 + 14 + 15)/2

= 42/2

s = 21 m

Area = √21(21 - 13)(21 - 14)(21 - 15)

= √21(8)(7)(6)

= √7 × 3 × 4 × 2 × 7 × 3 × 2

= 7 × 3 × 2 × 2

= 21 × 4

Area = 84 m²

Cost of advertising per year for 1 m² = Rs. 2000

Advertisement cost per year for 84 m² = 2000 × 84

= Rs.168000

Rent paid by the company for 6 months = 168000/2

= Rs. 84000

Therefore, the rent paid by the company is Rs. 84000/-

✦ Try This: The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 16 m, 17 m and 19 m. The advertisements yield an earning of Rs 3000 per m² a year. A company hired one of its walls for 8 months. How much rent did it pay?

☛ Also Check: NCERT Solutions for Class 9 Maths Chapter 12

NCERT Exemplar Class 9 Maths Exercise 12.3 Problem 2

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?

Summary:

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. The rent paid is Rs. 84000/-

☛ Related Questions: