My birthday is on the sixteenth.

My father is forty years old.

My birthday is on the fourteenth.

Her forehead is very attractive.

This mirror is made with a convex lens.

His forehead is very prominent.

This mirror is convex in shape.

We need to think about this problem in multiple dimensions.

This regular dodecahedron is a geometric shape with perfect symmetry.

This solid is called a regular icosahedron, and it is made up of 20 equilateral triangles.