Question

A rectangular park is with length 40 m and breadth 30 m . What will be the cost of buliding a fence diagonally across the park , given the charge is ₹ 70 per metre?

• A. ₹3500/-
• B. ₹2500/-
• C. ₹5000/-
• D. ₹3000/-

Answer 1

The correct option is A ₹3500/-


Length of the park = 40 m
Breadth of the park = 30 m
From the figure we observe that, the sides of the park along with the diagonal forms a right angled triangle.
$\therefore$ (The length of the fence)² = (Length)² + (Breadth)²
[Pythagoras theorem]
$\Rightarrow$ = 40² + 30² = 1600 + 900 = 2500
$\therefore$ The length of the fence = $\sqrt{2500}$ = 50 m
The cost to build the fence = ₹ 70 per metre
$\therefore$ The total cost = $50\times 70$ = ₹3500/-