Mathematics for IGCSE & O level - Similarity (Section 1 - No. 7)
If the surface area of a sphere is 100 cm², what would be the surface area of a similar sphere with a linear dimension three times as large?
300 cm²
600 cm²
900 cm²
1200 cm²
คำอธิบาย
If dimensions are 3x as large, the area is 3^2=9 times larger; 100 * 9 = 900 cm²