A cube is identified as a 3D solid object with 6 square faces.
Note the term SQUARE. Finding the area of a square, you simply multiply the measure of one side by itself.
Area = a²
The area given is 726 in². To get the measurement of each edge, we simply find the square root of 726 in²
Area = a²
726 in² = a²
√726 in² = √a²
26.94 in = a
The length of an edge is 26.94 inches.