Question

Calculate the area of the triangle whose sides are 12 cm, 17 cm and 25 cm.

• A. $190c{m}^2$
• B. $180c{m}^2$
• C. $10c{m}^2$
• D. $90c{m}^2$

Answer 1

The correct option is D

$90c{m}^2$

For $△BCD$,

b = 12 cm, c = 25 cm, and d = 17 cm
$semi-perimeter=s=\frac{25+17+12}{2}=27$

Area of the triangle = $A=\sqrt{s(s-c)(s-d)(s-b)}$

Using Heron's formula,
$A=\sqrt{27(27-25)(27-17)(27-12)}$

$=\sqrt{27\times 10\times 15}$

$=\sqrt{3^4\times {10}^2}$
$=90c{m}^2$