### Possible Answer

Apr 15, 2013 ... Angles in a quadrilateral (that is a 4 sided shape) add up to 360 degrees. So if you are asked to work out a missing angle in a quadrilateral then ... - read more

80° + 100° + 90° + 90° = 360°. A Square adds up to 360°. Let's tilt a line by 10° ... still adds up to 360°! The Interior Angles of a Quadrilateral add up to 360° ... - read more

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