Question

The perimeter of a triangle is 65 cm. The

lengths of the sides are x cm, x+8 cm, and
X+ 12 cm.
What is the length, in cm, of the longest side of
the triangle?

Answer 1

27cm

Explanation:

(xcm) + (x+8cm) + ( x+ 12cm) = 65cm

Open Bracket

xcm + x+8cm + x+12cm = 65cm

3x+ 20cm = 65cm

Collect like terms

3x = 65cm - 20cm

3x = 45cm

Divide both sides by 3

3x/3 = 45cm/3

x = 15cm

The longest side of the triangle =( x+12cm)

= (15+12)cm= 27cm

Answer 2

`▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪`

The longest side measures :

• 
  `27\: \: cm`

`\large \boxed{ \mathfrak{Explanation}}`

Perimeter of a triangle is equal to sum of measures of its all three sides, that is :

• 
  `x + x + 8 + x + 12`

and according to the question, the perimeter of the triangle is = 65 cm

so, let's equate both the expressions to find value of x :

• 
  `x + x + 8 + x + 12 = 65`
• 
  `3x + 20 = 65`
• 
  `3x = 65 - 20`
• 
  `3x = 45`
• 
  `x = 45 / 3`
• 
  `x = 15`

The longest side of the Triangle is :

• 
  `x + 12`
• 
  `15 + 12`
• 
  `27 \: \: cm`