Q) ABCD is a rectangle if the value of AB= 12 is given, find the values of x and y.

Ans: 

We know, opposite sides of a rectangle are equal,

∴ x + y = 12  —-(1)

and, x – y = 8   —-(2)

By elimination method, we subtract (2) from (1),

Therefore, 2y = 4

∴ y = 2

Substituting y=2 in equation (1), we get

x + 2 = 12

x = 10

Therefore value of x and y are: x = 10 and y = 2.