Question

The area of a parallelogram is given by the formula A=bh the area of the parallelogram on the right is 126 sq units. Find its base and height

Answer 1

Height = 5+1 = 6

Base = 4(5)+1 = 21

Explanation:

Answer 2

From the diagram we have

Base =
`4x+1`
Height =
`x+1`

Area = Base × Height
126 =
`(4x+1)(x+1)` ⇒ Expand the double bracket
126 =
`4x^(2)+5x+1` ⇒ Subtract 126 both sides
0 =
`4x^(2)+5x-125` ⇒ Factorise the quadratic expression
0 =
`(x-5)(4x+25)` ⇒ Equating each factor to zero


`x-5=0`
`4x+25=0`

`x=5`
`x=- (25)/(4)`

We need the positive value of
`x` so we use
`x=5`

Height = 5+1 = 6
Base = 4(5)+1 = 21