A square has four equal sides.<br><br>&bull; Perimeter = 4 × side<br>&bull; 36 = 4 × side → side = 36 ÷ 4 = 9 cm<br>&bull; Area = side × side = 9 × 9 = 81 cm&sup2;<br><br>Final Answer: B: 9 cm and 81 cm&sup2;