NCERT Solutions for Class 8 Maths Chapter 3 Understanding Quadrilaterals Exercise 3.4

Examples From Chapter 3 Understanding Quadrilaterals

Ex. 1 If ABCD is a rhombus. Let AB = 4 cm then evaluate the perimeter of ABCD?

Soln: A quadrilateral with all sides of equal length is called a rhombus. 

Hence,

The perimeter of ABCD = the sum of all four sides
therefore,

The perimeter of ABCD = (4 + 4 + 4+ 4) cm
= 16 cm

Ex. 2 If EFGH is a rectangle in which J is the point of intersection of the diagonals. Determine x, if JF = 8x + 4, EG = 24x – 8.

Soln: 

We know, EFGH is a rectangle in which diagonals are intersecting at the point J.

The diagonals of a rectangle insect each other and are equal
Hence,

EG = 2 × JF
⇒ 24x – 8 = 2 (8x + 4)
⇒ 24x – 8 = 16x + 8
⇒ 24x – 16x = 8 + 8
⇒ 8x = 16
⇒ x = 2