Measure each of the 4 angles with a protractor and they should total 360 degrees.
With a protractor
The 4 interior angles of any 4 sided quadrilateral add up to 360 degrees and using a protractor will prove it.
360
It has 360 degrees altogether no matter what. The sum of the four angles of any quadrilateral is 360o.360
360. Any quadrilateral's angles add up to 360.
The four angles of a quadrilateral add up to 360 degrees.
The sum of the 4 interior angles of any quadrilateral add up to 360 degrees.
360
360
360
The 4 interior angles of a quadrilateral add up to 360 degrees
A quadrilateral has 4 interior angles that add up to 360 degrees