Geometry
posted by DJ on .
A regular hexagon is made from equilateral triangle by cutting along the dotted lines and removing the three smaller triangles. if triangle has a perimeter of 18, what is the perimeter of hexagon?

Where are the dotted lines?

If an equilateral triangle has a perimeter of 18,the length of each side of the triangle is six(18/3=6). Therefore, the perimeter of the hexagon is thirtysix(6x6=36).
If a straight line is drawn from the center to each vertex, six congruent equilateral triangles are formed. The perimeter of the hexagon is equal to the sum of the six sides(36).