Question

A traffic signal is in the form of an equilateral triangle. The cost of colouring it at the rate of Rs 2per square centimetre is Rs 498.24. The edges of the sign are to be taped with red tape. Find the cost of the tape used at the rate of Rs 1.5 per square centimetre.

Answer 1

Answer-

The cost of the tape used is 108 rupees.

Solution-

A traffic signal is in the form of an equilateral triangle.

The cost of coloring it at the rate of Rs 2 per square centimeter is Rs 498.24

So, the area of the traffic signal is,

$=\frac{498.24}{2}=249.12\ cm^2$

We know that area of an equilateral triangle with side length as a is,

$Area=\frac{\sqrt{3}}{4}a^2$

So, in this case,

$\Rightarrow \frac{\sqrt{3}}{4}a^2=249.12$

$\Rightarrow a^2=249.12\frac{4}{\sqrt{3}}$

$\Rightarrow a^2=575.32$

$\Rightarrow a=\sqrt{575.32}$

$\Rightarrow a=23.99$

$\Rightarrow a\approx 24$

Then perimeter of triangle is,

$Perimeter=3\times a =3\times 24=72$

Cost of tape used is,

$=72\times 1.5=108$

Therefore, the cost of the tape used is 108 rupees.

Answer 2

Answer:

the cost of tape is 108 .....................,....