Question

One side of a right-angles triangular scarf is 80 cm and its longest side is 1 m. Find its cost at the rate of Rs 250 per $m^2$.

Answer 1

Let there is a right-angled triangle with sides AC, AB and BC, and AC be the longest side of this triangle.

So, in Δ ABC AC = 1 m, AB = 80 cm or 0.8 m and BC = ?

$A{C}^2=A{B}^2+B{C}^2$

$1^2={0.8}^2+B{C}^2$

$B{C}^2=1-0.64$

$B{C}^2=0.36$

$BC=0.6m$

Now, the area of the triangle = $\frac{1}{2}\times base\times height$

= $\frac{1}{2}\times 0.6\times 0.8$

Area of triangle = $0.24sqm$

Cost of scarf =$250\times 0.24$

=$Rs60$