Question

find the area of triangle whose two sides are 13cm and 14cm and its semi perimeter is 18cm give your answer to the nearest cm2 root 10 = 3.162

Answer 1

Given ,
let a and b are two sides and c be the third sides .
Since area of triangle =
$\sqrt{s(s - a)(s - b)(s - c)}$


here, a = 13cm
b = 14cm
c = ?
but semiperimeter = 18cm
so perimeter = 2×18= 36cm
since perimeter = a+b+c
36 = 13+14+c
c= 9
Now
area of triangle =
$\sqrt{18(18 - 13)(18 - 14)(18 - 9)}$
$\sqrt{18 \times 5 \times 4 \times 9}$
$2 \times 3 \times 3 \sqrt{10}$
$18 \sqrt{10} cm ^{2}$

Answer 2

Step-by-step explanation:

Given ,

let a and b are two sides and c be the third sides .

Since area of triangle =

\sqrt{s(s - a)(s - b)(s - c)}s(s−a)(s−b)(s−c)

here, a = 13cm

b = 14cm

c = ?

but semiperimeter = 18cm

so perimeter = 2×18= 36cm

since perimeter = a+b+c

36 = 13+14+c

c= 9

Now

area of triangle =

\sqrt{18(18 - 13)(18 - 14)(18 - 9)}18(18−13)(18−14)(18−9)

\sqrt{18 \times 5 \times 4 \times 9}18×5×4×9

2 \times 3 \times 3 \sqrt{10}2×3×310

18 \sqrt{10} cm ^{2}1810cm2