An apothem of a square is a perpendicular from a center of a square to one of its side. <span> </span><span>1. Put a dot at the center of the
square. (You can find the center by drawing diagonals from corner to
corner. The center is where they intersect).</span>
2. <span>Draw a perpendicular line in any of the four directions to one side of the square.</span><span />
3. <span>Two apothems of a square (drawn to opposite sides) make a line that is parallel
to both (left) sides of the square, a line that is of equal length. If two
apothems added together are equal to the length of one side, then one apothem is half of the length.</span> <span /><span> </span><span>4. The square perimeter is 40 and it consists of 4 equal parts, then the length of square's side is 10. </span><span> </span><span>5. Then the apothem has length 5. </span>
