Which of the following is not a characteristic of a regular polyhedron? A. It is also considered to be a convex polyhedron.
B. The number of edges meeting at each vertex is the same for all vertices.
C. All of the faces are congruent.
D. It is not a Platonic solid.

20 Pts so 10 for 2 people who answer it​

Acircular hot tub located near the middle of a rectangular patio has a diameter of 48 inches. the patio measures 11 feet by 6 feet. what is the area of the patio that is not covered by the hot tub?

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

Which is the focus of a parabola with equation y2=4x