Because the angle sum of all quadrilaterals is 360 degrees.
The four interior angles of a trapezoid add up to 360 degrees
the Sum of the Interior of a triangle is 180
There is no regular polygon with an interior angle of 20o. If the interior angle is 120o then there are six sides and the sum of the angles is 720o.
The sum of the interior angles is 360 degrees.
360 degrees
The 4 interior angles add up to 360 degrees
The sum of the four interior angles of a trapezoid is 360 degrees.
The sum of the 4 interior angles of a trapezoid add up to 360 degrees.
The 4 interior angles of a trapezoid add up to 360 degrees
The 4 interior angles of a trapezoid add up to 360 degrees
A regular trapezoid (!) is a square. And each interior angle of a square is 90 degrees.
The 4 interior angles of a trapezoid add up to 360 degrees
Because the angle sum of all quadrilaterals is 360 degrees.
360 degrees
360 degrees
360 degrees