1. Finding missing side
- Quadrilateral

2. Example 1: Ans: diagonal (d)= 12 m2
The area of a quadrilateral is 210 sq. m. The perpendiculars from two vertices to
the diagonal are 10 m and 25 m. What is the length of this diagonal ?
Solution:
Given:
Area = 210 sq.m, h1 = 10m , h2 = 25m To find: diagonal (d )
Area of a quadrilateral = x d x [h1 + h2]
210 = x d x [ ]
x d x [ ] = 210
x d x = 210
d x = 210 x 2 (Transposing 2 to the RHS)
d x 35 = 420
(Transposing 35 to the RHS) 84
= 12
(Dividing 420 and 35 with 5) 7
Ans: diagonal (d)= 12 m2

3. Example 2: Ans :- Height h2= 14 cm
The area of a quadrilateral is 126 sq. cm. The diagonal is 12cm and h1 is 7.
What is the length of this diagonal ?
Solution:
Given: Area = 126 sq.cm, h1 = 7cm , d = 12cm To find: diagonal (d )
Area of a quadrilateral = x d x [h1 + h2]
12 = x 12 x [7 + h2]
x 12 x [7 + h2] = 12
6 x [7 + h2] = 126
7+ h2 = (Transposing 6 to the RHS)
7+ h2
7+ h2 = 21
h2 = (Transposing 7 to the RHS)
h2 = 14cm 63
= 21 3
Ans :- Height h2= 14 cm

4. Try these
1. Find base of quadrilateral if area of quadrilateral is 210 m2 and perpendicular vertices are 3cm and 5cm.
2. If area of quadrilateral is 210 m2 and the diagonal is 30 m and one of the perpendicular vertices is 6m. Then, find the another perpendicular vertices?