The perimeter of a scalene triangle is 14.5cm. 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 6.2cm

See basic equations.

Step-by-step explanation:

Let x = the shortest side

Let 2x = the longest side.

Let y = the medium sized side.

Basic Equation

y + x + 2x = 14.5

or

y + 3x = 14.5

Comment

This almost looks like it needs more information because you are not entirely certain what you are looking for. You have not asked for a complete solution. About all you can do is solve for x and y and see if you really do have a triangle.

y + x + 2x + 14.5

2x = 6.2 Given. Divide by 2

x = 6.2/2 = 3.1

x + 2x + y = 14.5 Substitute values

3.1 + 6.2 + y = 14.5 Combine like terms

9.3 + y = 14.6 Subtract 9.3 from both sides

y = 14.6 - 9.3 Combine

y = 5.3

Yes you do have a triangle. any 2 sides is larger than the 3rd.

I don't know what to put as the answer however.