Choosing formulas by the quantity named
Circle the target word — length, area, volume, angle — before opening the formula list.
Key formulas
Word → tool
“How much space inside” → volume. “Paint the outside” → surface area. “Steepness” → angle or gradient.
Same solid, different asks
A cylinder question can request V=πr²h or curved area 2πrh. The solid does not choose; the wording does.
Drill
Cover the formulas and say aloud which family a question needs, then uncover to confirm.
Worked example
Worked example
Problem. A cylinder question asks for “paint needed for the curved outside” and separately for “how much water it holds”. Which formulas?
Solution. Paint → curved surface 2πrh. Water → volume πr²h. Same solid, different target quantities.
False friend
“Capacity” is volume; “floor space” is area.
Review quiz
“How much water fits in the cylinder?” needs:
Practice questions
- Sort five exam sentences into length/area/volume/angle.
- Give two formulas that students mix up for cones.
Study notes
What if two quantities are asked?
Answer in separate lines with separate units.