Respuesta :

Answer: 6units

Step-by-step explanation:

Since it is a regular polygon, and it has 3 equal sides it means the polygon is a quadrilateral.

From the diagram,

5 - 2x = -4x + 9 ( side of quadrilateral )

Solving for x in the equation

-2x + 4x = 9 - 5 ( collection of like terms in simple linear equation )

2x = 4

Divide through by the coefficient of x which is 2

x = 2.

Therefore, the perimeter of the polygon which equals to the total length of the polygon is

Perimeter = 2 + 2 + 2

= 6units