EHF is tangent to the purple circle at E, and EN is tangent to the red circle at N. A and C are the circle centers. A blue rectangle has three corners HEC and the point A on one side. What is the ratio of areas, green square to orange quadrilateral?

# Tag: rectangle

## All connected

Four coloured rectangles and three line segments. Prove that the three line segments are concurrent.

## Ends of the spectrum

Two squares and a rectangle. Prove that red = blue.

## Nearly the same

Two rectangles are positioned with the side of each one along the diagonal on the other. Furthermore, two of their sides have the same length, as marked. What is the quotient of areas (A+B)/(C+D)?

## The blue lagoon

Five congruent brown triangles inside a rectangle. What fraction is brown?

## Rectangle offspring

Three rectangles of which the blue and the pink one are similar. Prove that the yellow rectangle is also similar.

## Lifting the veil

A blue triangle and a red rectangle with an extended side. Prove they have equal area.

## Stars on 45

A square containing a rectangle. What is the red fraction?

## Under the dome

Two semicircles with four squares and a yellow rectangle. What is the aspect ratio of the latter?

## Antennas above and below

The triangle ABC has orthocentre H, so that HA is an antenna above the green hill. The rectangle BCDE is inscribed in the circumcircle (ABC). Show that HA = CD = BE.