Find the cost of laying grass in a triangular field of sides 50 m, 65 m and 65 m at the rate of Rs. 7 per m².

Solution:

Given, the sides of a triangular field are 50 m, 65 m and 65 m.

We have to find the cost of laying grass at the rate of Rs. 7/m² in the field.

Consider a triangle ABC

The sides AB and AC are equal.

So, ABC is an isosceles triangle

Area of isosceles triangle = a/4 √4b² - a²

Where, a = base

b = length of equal side

Here, a = 50 and b= 65

Area = 50/4 √4(65)² - (50)²

= 50/4 √4(4225) - (2500)

= 50/4 √16900 - 2500

= 50/4 √14400

= 50/4 √144 × 100

= 50/4 (12 × 10)

= 500(3)

Area of triangle ABC = 1500 m²

Cost of laying grass in 1 m² = Rs. 7

Cost of laying grass for entire field = 1500 × 7

= 10500/-

Therefore, the cost of laying grass in a triangular field is Rs. 10500/-

✦ Try This: Find the cost of laying grass in a triangular field of sides 30 m, 35 m and 65 m at the rate of Rs. 8 per m².

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

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NCERT Exemplar Class 9 Maths Exercise 12.3 Problem 1

Find the cost of laying grass in a triangular field of sides 50 m, 65 m and 65 m at the rate of Rs. 7 per m²

Summary:

The cost of laying grass in a triangular field of sides 50 m, 65 m and 65 m at the rate of Rs. 7 per m² is Rs. 10500/-

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