What equation would you use to solve?

Question

The longest side of a triangle is 2 times the shortest side. If the third side is 5 more than the shortest side, and the perimeter is 65cm, find the measures of the three sides of the triangle.

Answer 1

Let x = the length of the shortest side.

• The longest side of a triangle is 2 times the shortest side: = 2x
• The third side is 5 more than the shortest side = x + 5

 

The perimeter of the triangle is the sum of the lengths of the sides and is equal to 65cm

 

      x + 2x + x+5 = 65

 

      4x + 5 = 65

 

      4x = 60 cm

 

      x = 15

 

The shortest side = x = 15 cm

The longest side = 2x = 2*15 = 30 cm

The third side = x+5 = 15 + 5 = 20 cm

 

15 + 30 + 20 = 65 cm