Geometry
# Geometry Warmups

$A, B, C, D$ are equally spaced points on a line. Semicircles are constructed on both sides, and colored in, as in the above image.

Which region is the smallest?

To draw an alien's head, Mary drew a large circle, and then added 2 equal black circles for the eyes. She colored the smaller circles black, and colored the rest of the figure grey.

Which region is larger, the grey region or the black region?

In the above square of side length 2, we draw in 2 quarter circles and shade them blue and red respectively.

What is the area of the purple oval region, where these quarter circles overlap?

The above blue cross is formed by two 2 by 7 rectangles. What is its area?