Question

b) Rakesh bought an article for ₹1400 and sold it for ₹1190. Calculate his profit% or loss % [3]
c) The sides of a triangle are 21cm, 17cm and 10cm.Find its area.

Answer 1

b) Rakesh bought an article for ₹1400 and sold it for ₹1190. Calculate his profit% or loss %.

Given :

• Cost Price = Rs. 1400
• Selling Price = Rs. 1190

To find :

• profit% or loss %

Solution :

Since,

C.P > S.P [Here, it is loss]

Loss = S.P - C.P

        = 1400 - 1190

        = 210

$\sf Loss \% = \dfrac{loss}{c.p} \times 100$

          $\sf = \dfrac{210}{1400} \times 100$

          $\sf = \dfrac{21000}{1400}$

          = 15 %

Therefore, loss% is 15%.

c) The sides of a triangle are 21cm, 17cm, and 10cm. Find its area.

Given :

• Sides = 21cm, 17cm and 10cm

To find :

• Area

Solution :

Semi Perimeter = $\sf \dfrac{a + b + c}{2}$

                          = $\sf \dfrac{21 + 17 + 10}{2}$

                          = $\sf \dfrac{48}{2}$

                          = 24 cm

Area using Heron's Formula = $\sf \sqrt{s (s-a) (s-b) (s-c)}$

                                               = $\sf \sqrt{24 (24-21) (24-17) (24-10)}$

                                               = $\sf \sqrt{24 \times (3) \times (7) \times (14)}$

                                               = $\sf \sqrt{7056 }$

                                               = 84 cm²

Therefore, the Area of the Triangle is 84 cm².