Mathematics for IGCSE & O level - Algebraic Manipulation (Section 6 - No. 41)
If a square has a side length of 'a', what expression represents its perimeter?
a^2
4a
2a
a + 4
解释
The perimeter of a square is the sum of all its sides, and since all sides are equal to 'a', the perimeter is 4 * a = 4a.