A square has a side length of x + 3. A regular octagon has a side length of 3x. If the polygons have the same perimeter, determine the value of x.

x = ⅗ = 0.6

Step-by-step explanation:

A square has four equal sides.

If a square has a side length of , therefore,

Perimeter of the square =

.

Also, a regular octagon has 8 equal sides.

If it has a side length of 3x, therefore:

Perimeter of the octagon =

=

Given that the Perimeter of the rectangle and the octagon are the same, to find the value of x, set each perimeter equal to the other.

Thus:

Subtract 4x from each side

Divide both sides by 20

x = 12/20 = ⅗ = 0.6.

6e14 is the answer.