Surface area
The area of all the faces of a prism or cube. Read one part at a time and tap “I know this”. Then test yourself in the quiz.
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Surface area
Surface area is the total area of all the faces of a 3D object. Think of the net: unfold the object.
- Cube: 6 equal squares → SA = 6 × s².
- Rectangular prism: 3 pairs of rectangles → SA = 2(lb + lh + bh).
Cube with s = 3 cm: 6 × 3 × 3 = 54 cm².
Rectangular prism of 4 cm × 3 cm × 2 cm: SA = 2(4 × 3 + 4 × 2 + 3 × 2) = 2(12 + 8 + 6) = 2 × 26 = 52 cm².
Remember this and test yourself
- Surface area = sum of all faces.
- Cube: 6 × s².
- Prism: 2(lb + lh + bh).
- Units are square: cm².
Write these points in your book. Read them again the night before the test.
Wrapping paper: surface area is how much paper you need.
Important words
First say the answer yourself, then turn the card over.
Match column A to column B
Tap a word in column A, then its meaning in column B. You can also start in column B.
Now the real quiz!
The quiz has many more questions on this topic. Every question shows straight away whether you are right and explains why.
Take the quiz: Surface area- Let your child work the examples on paper and explain them to you.
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Follows CAPS for Grade 7 Mathematics. Always check your teacher’s notes and textbook too.