Surface Area of 3D Shapes Flashcards

Grade 6 · Math · Flashcards

Formulas, vocabulary, and key facts for surface area of 3D shapes in Grade 6.

Flashcards

Surface area: Total area of all faces of a 3D solid — measured in square units
Net: A 2D layout that folds into a 3D shape, showing all faces
Face: A flat surface on a 3D shape
Rectangular prism SA: SA = 2lw + 2lh + 2wh
Cube SA: SA = 6s² — all 6 faces are identical squares
How many faces does a cube have?: 6 — and they're all congruent squares
SA units: Always square units: cm², in², m² — never cubic
Rectangular prism: opposite faces: Come in 3 congruent pairs — that's why the SA formula has three '2×' terms
SA of a 2×3×4 box: 2(6) + 2(8) + 2(12) = 12+16+24 = 52 square units
SA of a cube with side 5: 6 × 5² = 6 × 25 = 150 square units
Why SA matters (real life): Painting a room, wrapping a gift, tiling a floor — all require surface area calculations
Difference: SA vs Volume: SA measures the outside covering (square units); Volume measures the inside space (cubic units)