There's a trick to solving the area of a triangle, and it involves a skill your geometers have already mastered. Help them discover the connection between finding a rectangle's area and finding a right triangle's area as they solve for nine of them. There is an example here that exposes the trick, so consider only handing this out after scholars have explored this connection on their own. All of these triangles have whole-number measurements along adjacent sides, and the square units are already written into each answer.

Common Core

3.MD.C.7.a