Several line segments, some of which are parallel. What is green : orange?
Tag: parallelogram
Dancing squares
Four squares and one centre. Prove that the red quadrilateral is a parallelogram.
Triangles galore
Four equilateral triangles. Two centres are shown. Prove that the green quadrilateral is a parallelogram.
The lighthouse
A parallelogram and four equilateral triangles. What is yellow : green?
Pink parallels
A pink parallelogram with two extended sides. What’s α : β?
Three’s a crowd
Four equilateral triangles. Prove that the red quadrilateral is a parallelogram.
The gyroscope
Two ellipses go through each others focal points. Prove that the focal points are the vertices of a parallelogram.
The beam in your eye
Three parallelograms are inscribed in a circle. Prove that the common red vertex is the orthocentre of the dashed triangle.
The iron curtain
A parallelogram ABCD with a circle and a diameter CE. Prove that point E is the orthocentre of triangle ABD.
The crazy quilt
A parallelogram is divided into several areas. What is the area X of the blue trapezium?