Question

Find the area of a triangle whose sides are 18 cm, 10 cm and 14 cm.​

Answer 1

Given:

A = 18cm

B=10cm

C=14 cm

To find:

area of a triangle

.•♫•♬•Solution •♬•♫•.

$semi \: perimeter \: = \frac{a + b + c}{2}$

$semi \: perimeter = \frac{18 + 10 + 14}{2}$

$semi \: perimeter \: = \frac{42}{2} = 21$

By heron's formula

$\sqrt{S(S - a)(S - b)(S - c)}$

$\sqrt{21 (\: 21 - 18)(21 - 10)(21 - 14}$

$\sqrt{21 \times 3 \times 11 \times 7}$

We can also write 21 as 7× 3

$\sqrt{7 \times 3 \times 3 \times 11 \times 7}$

$\sqrt[21]{11}$

Hence the area of triangle is 21√11