Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help: Perimeter and Area of Triangles and Trapezoids
Get independent practice working with finding the perimeter and area of triangles and trapezoids. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
Khan Academy
Khan Academy: Area and Perimeter on the Coordinate Plane
Find the area or perimeter of shapes like triangles, rectangles, parallelograms, and hexagons on the coordinate plane. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.