In a regular quadrangular pyramid, point O is the center of the base, S is the vertex, SO = 40 Ac = 60.

In a regular quadrangular pyramid, point O is the center of the base, S is the vertex, SO = 40 Ac = 60. Find the lateral edge SA.

Since the pyramid is regular, there is a square at its base, the diagonals of which, at the point of their intersection, are divided in half. Then AO = CO = AC / 2 = 60/2 = 30 cm.

SO is the height of the pyramid, then triangle AOS is rectangular. By the Pythagorean theorem, we determine the length of the hypotenuse SA.

SA ^ 2 = AO ^ 2 + SO ^ 2 = 900 + 1600 = 2500.

SA = 50 cm.

Answer: The length of the side rib is 50 cm.