Question

The first side of a triangle is 9 m shorter than the second side. The third side is 3 times as long as the first side. The perimeter is 39 m. What is the length of the longest side?

Answer 1

Answer:

The length of the longest side is 18 m.

Step-by-step explanation:

Let x = length of the second side.

Then the length of the first side is x - 9.

The length of the third side is 3(x - 9).

Add the three lengths and set equal to the perimeter.

x + x - 9 + 3(x - 9) = 39

2x - 9 + 3x - 27 = 39

5x - 36 = 39

5x = 75

x = 15   (second side)

x - 9 = 15 - 9 = 6  (first side)

3(x - 9) = 3(15 - 9) = 3(6) = 18   (third side)

Answer 2

Answer:

Longest side is 18 m

Step-by-step explanation:

1st side : x -9

3rd : 3(x-9)

If perimeter is 39, then, x + (x-9) + 3(x-9) = 39

5x -36 = 39

5x = 75

x = 15

Therefore,

1st side = 6

2nd side = 15

3rd side = 18