Constructing a Rectangle with a Given Base

Construction Algorithm
1 Construct a line AB as a given base of the rectangle.
2 Construct a perpendicular line to AB through the point B.
3 Construct a point C on the perpendicular line.
4 Construct a circle centered at A and has a radius BC.
5 Construct another circle centered at C and has a radius AB.
6 Generate the intersection points between the two circles to find the fourth vertex of the rectangle.
7 Join up the four points A, B, C, and D to get the required rectangle.
8 Switch to drag mode. Pick a free element. Move it around to check your construction.

Construction Theorems

A rectangle is a parallelogram with a right angle.

A parallelogram is a quadrilateral, in which each two opposite sides are equal in length.

Please enable Java for an interactive construction (with Cinderella).
Please enable Java for an interactive construction (with Cinderella).