Question

Find the area of a triangle two sides of which are 18cm and 10cm and the perimeter is
R 42cm.*
lo are in the ratio of 12:17:25 and its perimeter is 540cm. Find its area. K​

Answer 1

Answer:

Area of triangle

s(s−a)(9−b)(s−0)

Here, s is the semi- perimeter,

and a,b,c are the sides of the triangle

Given a=18 cm, b=10 cm

and perimeter =42 cm

semi- perimeters=

2

perimeter

=

2

42

s=21cm.

Area of triangle

∴c=42−(18+10)cm =14 cm

∴ Area of triangle=

21.(21−18)(21−10)(21−14)

=

21.3.7.11

cm

2

=

3×7×3×7×11

cm

2

=

(3×7)

2

×11

cm

2

=21

11

cm

2

∴ Thus, the required area of the triangle is

21

11

cm

2

Answer 2

Answer:

area =

$21 \sqrt{11}$

semi perimeter =

$21$