alleryA square garden has area 2025 m². What is its side?
A35 m
B40 m
C45 m
D50 m
Answer & Solution
Correct answer: C. 45 m
side = √area = √2025. Using the (a5)² shortcut in reverse: a(a+1) hundreds + 25 = 2025 means a(a+1) = 20, so a = 4 (since 4·5 = 20).
Hence side = 45 m.
**Check:** 45² = 4 × 5 × 100 + 25 = 2025 ✓
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