Question

1. The sides of a triangular plot are in the ratio of 3:5:7 and its perimeter is 300 m. Find its area.
(b) 830
(c) 1230
(d) 16/30
(a) 430
2. Find the area of a triangle, two sides of which are 8 cm and 11 cm and the perimeter is 32 cm
(b) 3000 3
(c) 4500 V3 (d) 6000 13
(a) 1500 V3
3. Find the area of a triangle two sides of which are 18em and 10cm and the perimeter is 42cm.
(b) 21VIT
(c) 35/11
(d) 21/11
(a) 14/11
4. Sides of a triangle are in the ratio of 12; 17: 25 and its perimeter is 540cm. Find its area.
(d) none of these
(b) 9000
(c) 12000
(a) 6000​

Answer 1

Answer:

The sides of a the triangular plot are in the ratio 3:5:7. So, let the sides of the triangle be 3x, 5x and 7x.

Also it is given that the perimeter of the triangle is 300 m therefore,

3x+5x+7x=300

15x=300

x=20

Therefore, the sides of the triangle are 60,100 and 140.

Now using herons formula:

S=

2

60+100+140

=

2

300

=150 m

Area of the triangle is:

A=

s(s−a)(s−b)(s−c)

=

150(150−60)(150−100)(150−140)

=

150×90×50×10

=

6750000

=1500

3

m

2

Hence, area of the triangular plot is 1500

3

m

2

.