Square A has side 5 cm. Square B has area 100 cm&sup2;, so its side is 10 cm. The ratio of their side lengths is 5 : 10.<br><br>[[model:questions/solutions/q4505.png]]<br><br>• Area of Square B = length × length = 100 cm&sup2;<br>• Length of Square B = &radic;100 = 10 cm<br>• Ratio of length A to length B = 5 : 10<br>• Simplify by dividing by 5 → 5 ÷ 5 = 1, 10 ÷ 5 = 2<br><br>The ratio of the length of square A to the length of square B is 1 : 2.<br>Check: Length A = 5 cm, Length B = 10 cm. 5 : 10 = 1 : 2. ✓