A rectangle has a diagonal of 41 cm and a surface size of 20 square centimetres. The rectangle's perimeter must be:
A. 9 cm
B. 18 cm
C. 20 cm
D. 41 cm
Answer:B
A rectangle has a diagonal of 41 cm and a surface size of 20 square centimetres. The rectangle's perimeter must be:
A. 9 cm B. 18 cm C. 20 cm D. 41 cm
Explanation: 41 = l2 + b2.In addition, lb = 20.2lb = 41 + 40 = 81 (l + b)2 = (l2 + b2) + 2lb = 41 + 40 = 81,(9 + l + b).2(l + b) = 18 cm is the perimeter.