Question

in a triangle the side are 28cm, 35cm and9cm. find the area of triangle

Answer 1

Solution:

a= 28cm

b= 35cm

c= 9cm

$\bold{s = \frac{28 + 35 + 9}{2} = 36}$

By, herons formula,

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

$\bold{ = \sqrt{36(36 - 35)(36 -28 )(36 - 9)}}$

$\bold{ = \sqrt{36(1)(8)(27)} }$

$\bold{ = \sqrt{6 \times 6 \times 2 \times 2 \times 2 \times 3 \times 7} }$

$\bold{ = 6 \times 2 \sqrt{2 \times 3 \times 7}}$

$\bold {= 12\sqrt{6 \times 7} }$

$\bold{= 12 \sqrt{42} }$

=77.7688 cm²