Question

An umbrella is made by stitching 10 triangular pieces of cloth of two different colours where each pieces measuring 48cm,48cm,and 30cm. find cost of required to make umbrella at rate of 5paisa per square cm.
help plz plz .......

Answer 1

Given:

An umbrella is made by stitching 10 triangular pieces of cloth.

Each pieces measuring 48cm,48cm, and 30cm.

To find:

The cost of required to make umbrella at rate of 5 paisa per square cm.

Solution:

Area of a triangle is:

$A=\sqrt{s(s-a)(s-b)(s-c)}$

Where,

$s=\dfrac{a+b+c}{2}$

Each pieces measuring 48cm,48cm, and 30cm. So,

$s=\dfrac{48+48+30}{2}$

$s=\dfrac{126}{2}$

$s=63$

Area of one triangular piece is:

$A=\sqrt{63(63-48)(63-48)(63-30)}$

$A=\sqrt{63(15)(15)(33)}$

$A=\sqrt{467775}\text{ cm}^2$

$A\approx 683.9408\text{ cm}^2$

Area of 10  triangular pieces is:

$10\times 683.9408=6839.408\text{ cm}^2$

The rate is 5 paisa per square cm. So, the total cost is:

$6839.408\times 5=34197.04$

Therefore, the total cost is 34197.04 paisa.