Question

the sides of a traingle are 21cm,17cm,10cm.find its area
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Answer 1

Answer:

84 cm²

Step-by-step explanation:

Let a , b , and c be the 3 sides of the triangle.

Given : a = 21 cm , b = 17 cm , c = 10 cm

Semi-perimeter of the triangle = s = $\frac{a + b + c}{2}$

= $\frac{21 + 17 + 10}{2}$

= $\frac{48}{2}$

= 24 cm.

Using Heron's formula,

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

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

= $\sqrt{24 * 3 * 7 * 14 }$

= $\sqrt{7056}$

= 84 cm²

So, the area of the triangle is 84 cm².