Q2 of 31 Page 45

How much will it cost to have a triangular field weeded at the rate of Rs 2 per square metre if the length of the field’s sides are 11 m, 61 m and 60 m?

Given:


Length of one side of the triangle (a) = 11 m


Length of second side of the triangle(b) = 61 m


Length of third side of the triangle (c) = 60 m


Semi perimeter (s) =


According to Heron’s formula


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


⇒ Area of the triangle = 330 sq m


Rate of weeding = Rs 2 per sq m


Total cost = (330 × 2) = Rs 660


More from this chapter

All 31 →
4

The area of a trapezium is 84.5 sq cm and its height is 6.5 cm. If one of its parallel sides is 15.2 cm long, what is the length of the other side?

 1

If the sides of a triangle are 25 cm, 39 cm, and 56 cm, what is the area of this triangle?

 3

If the length of the sides of a triangular plot of land are 20 m, 21 m and 13 m, what is its area?

 4

Use Heron’s formula to find the area of an equilateral triangle whose side is ‘p’.