A cube has an edge of 2a cm. Find its surface area.
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Answer: D. 24a2 cm2
Explanation
The total surface area of a cube is calculated by multiplying six by the square of its edge length. Substituting the given edge length of two a into the surface area formula gives six times the square of two a. Squaring two a results in four a squared, which when multiplied by six yields twenty four a squared. A cube is a regular three dimensional solid featuring six identical square faces meeting at right angles. Surface area measures the total external boundary coverage area of a three dimensional geometric object. Algebraic expansion rules require squaring both the numerical coefficient and the variable term.
Option A forgets to account for the coefficient when squaring the edge length of the cube. Option B underestimates the total surface area by using an incorrect numerical multiplier. Option C incorrectly multiplies by three instead of six faces when computing total surface area.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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