There are 20 points arranged in a cross pattern shown below. How many squares can be drawn, using any 4 points as corners?
A circle contains 4 identical squares, as shown below. If each square has a side length equal to 2, what is the radius of the circle?
A circle circumscribed 5 squares with side length 1, as shown below. (The squares are in a 2×2 grid and one circle on the right middle). What is the radius of the circle?
In the diagram below, there are 4 squares and 3 areas are known. What is the radius of the circle?
How many triangles are there in a regular pentagon with all its diagonals drawn?
Note: a regular pentagon has five straight sides all of the same length and five equal angles. A diagonal is a line joining points.