Surface area of pyramids

Target: Add the base and four triangular faces using the face height.

Language target: Distinguish face height from vertical height.

Likely miss: Students use the vertical height of the pyramid as the triangle’s height on the net.

Ask: Which height is drawn on the net?

If you see it: The triangle height on the net is the slant height given for the face, not the pyramid’s vertical height.

Evidence to listen for: The student adds base area and four triangle areas.

Next: If the vertical height was used, label the two heights differently.

Observable student moves: names both quantities, uses the represented relationship, and revises after feedback. This companion is not a score.