IX Assignments Maths:Heron’s Formula

Assignments Topic :  Heron’s Formula

1)    Find the area of the triangle whose sides are 13cm, 14cm and 15cm.

2)    Prove that the length of the altitude of an equilateral triangle of side ‘a’ is.√3/2a

3)    The sides of a triangular field are 120m, 160m & 200m. Find the cost of ploughing it at the cost of 25 paise per square m.

4)    The length of sides of a right angled triangle forming the right angle are  5x cm and (3x – 1) cm. If the area of the triangle is 60 cm2, find its all sides.

5)    Find the perimeter of an isosceles right angled triangle having area 200 cm2.

6)    Find the area of a quadrilateral ABCD in which AB = 3cm, BC = 4 cm, CD = 4 cm, DA = 5 cm and AC = 5cm

7)    A triangle and a parallelogram have the same base and the same area. If the sides of the triangle are 26cm, 28cm and 30cm, and parallelogram stands on the base 28cm, find the height of the parallelogram.

8)    A field is in the shape of trapezium whose parallel sides are 25m and 10m. The non-parallel sides are 14m and 13m. Find its area.

9)    A rectangular has twice the area of square. The length of rectangle is 12 cm longer and the width is 8cm longer than the sides of the square. Find the area of the square.

10) The adjacent sides of a parallelogram are 125 mm and 62.5 mm. If one altitude of parallelogram is 0.025m, find the other altitude in cm.

11) The diagonals of a rhombus are whose 15 and 36 cm long. Find its perimeter.

12) Find the percent increase in the area of an equilateral triangle if its each of the side is doubled.

13) Find the area of an equilateral triangle whose each side is ‘a’.

14) Find the area of ABCD in which AB = 9m, BC = 40m, CD = 15m and AD = 28m and angle ABC is 90o.

15) The area of an equilateral triangle is 2√3cm2 . Find its perimeter.

16) Find the area of an isosceles triangle whose each of equal side is ‘a’ and the other side is ;b;.

17) Find the area of triangle two sides of which are 18cm and 10cm and perimeter is 42cm.

18) The sides of triangle are in the ratio of   12 : 17 : 25 and its perimeter is 540 cm. Find its area.

19) Find the area of an equilateral triangle whose each side is 30m.

20) Find the area of a triangle whose sides are 122m , 22m and 120m respectively.