Number of Degrees in a Square

Knowing the correct number of degrees when designing something can be crucial to the successful outcome of the design. A square is a shape of four equal length sides joined at right angles. The interior angle measurement and the exterior angle measurement are the same on each of the four corners. You can measure the angles in a square with a protractor or by knowing the basic laws of geometry.

  1. Polygon Rule

    • The geometry rule about polygon angles is that they will add up to 360 degrees. You can find the interior or exterior by subtracting the other from 360.

    Interior Separate Angle

    • Each interior angle in a square is a 90-degree right angle. This is found with the formula: (Number of sides * 180) - 360 / (the number of sides). So 4 * 180 = 720. 720-360 = 360. 360/4 = 90 degrees.

    Total Interior Angles

    • The total number of degrees inside a square is found by adding all the angles together. In this case: 90+90+90+90= 360 degrees.

    Separate Exterior Angles

    • The geometry rule states that angles in a polygon add up to 360. Knowing this to find the external angle of a square we must subtract the interior angle from the total of 360. 360-90 = 270 degrees.