Interior angles in a triangle add up to 180˚. Triangles close triangleA polygon with three straight sides. have three sides, therefore they have three angles. Interior angles in a triangle sum to a ...

Get a fresh, colourful angle on the basics of geometry! What are angles? Do you know the difference between a triangle and a quadrilateral? These videos on the basics of geometry will help you ...

Take any quadrilateral such as ABCD above. Construct the midpoints of each side and join them to form another quadrilateral EFGH. Varignon's Theorem asserts that the ...

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