The perimeter of a scalene triangle is 14.5 cm. The longest side is twice that of the shortest side. Which equation can be used to find the side lengths if the longest side measures 6.2 cm?

14.5 = (6.2/2) + b + 6.2

Step-by-step explanation:

First, identify what you know:

1) The perimeter of the scalene triangle is 14.5 cm

2) The longest side is 6.2 cm

3) The shortest side is half the length of the longest side.

So, if the shortest side, is half the length, of the longest, then it would be 6.2 divided by 2.

6.2cm/2 = 3.1  cm

Now, we have the length of the shortest side (3.1 cm) and the length of the longest side (6.2).

Now, identify the formula to find the area of a triangle:

P = a + b + c

We already have three of our values in this formula!:

14.5 cm = 3.1 cm + b + 6.2

Now, we just have to reverse engineer the problem, and get be alone.

14.5 cm - 3.1 cm - 6.2 cm = b

14.5 cm - 9.3 cm = b

b = 4.5 cm

14.5 cm  = 3.1 cm + 4.5 cm + 6.2 cm