Describe the error kevin made. circle the places in the drawing of kevin's solution where he made an error

The error that Kevin made was he did not include two units (see the circled areas) while counting the units. He counted the units there as one instead of two at those junctions. The correct measure of the perimeter of the figure is 20 units.

(see attached image)

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .