Learning goals: Teacher Facing Critique (orally) different methods for decomposing and calculating the area of a prism’s base. Explain (orally and in writing) how to decompose and calculate the area of a prism’s base, and then use it to calculate the prism’s volume. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 7.7 Angles, Triangles, and Prisms, Grade 7.