A square has a 40-cm diagonal. How long is each side of the square? Round to the nearest tenth of a centimeter

28.3 cm

Step-by-step explanation:

Let x represent the length of one side of the square. Then, by the Pythagorean Theorem,

x^2 + x^2 = (40 cm) ^2, or

2x^2 = 1600 cm^2.

Thus, x^2 = 800 cm2, and x, the length of one side, is √800, or 28.3 cm to the nearest tenth of a cm.