Mathematics for IGCSE & O level - Similarity (Section 1 - No. 39)
Two similar figures have perimeters in the ratio 3:5. If the smaller figure has an area of 18 cm², what is the area of the larger figure?
30 cm²
50 cm²
75 cm²
125 cm²
คำอธิบาย
Length scale factor = 5/3. Area scale factor = (5/3)². Area = 18 * 25/9 = 50cm².