Question

The sides of a triangle are given as 3x, x - 1 and 3x + 1. If the perimeter [2]

is 56m find its sides.

Answer 1

The sides are 24cm, 7cm, and 25cm

Explanation:

3x+x-1+3x+1=56 <---- First we combine like terms (the 1's cancel out)

7x/7=56/7 <--- Divide by 7 to isolate the variable

x=8 <--- Now that we've solved for x we need to plug it back into each side

3(8)=24

(8)-1=7

3(8)+1=25

24+25+7=56 <---- Make sure it all adds up to 56

Hope this helps :)

Answer 2

The sides of the triangle are:

• 
  `3x = 3(8)=24`

• 
  `x-1=8-1=7`

• 
  `3x+1=3(8)+1=25`

Explanation:

• We know that the perimeter of a triangle is the sum of the length of its sides.

As the sides are given

• 3x

• x-1

• 3x+1

so the equation of the perimeter becomes

`P=3x+\left(x-1\right)+\left(3x+1\right)\:`

as

• P = 56m

so

`56=3x+\left(x-1\right)+\left(3x+1\right)`

`3x+x+3x-1+1=56`

`7x-1+1=56`

`7x=56`

`(7x)/(7)=(56)/(7)`

`x=8`

Now finding the sides

`3x = 3(8)=24`

`x-1=8-1=7`

`3x+1=3(8)+1=25`

Therefore, the sides of the triangle are:

• 
  `3x = 3(8)=24`

• 
  `x-1=8-1=7`

• 
  `3x+1=3(8)+1=25`