geometry

5. a common plane that intersect in a single point
9. an entire function and is implemented in the wolfram language as Cos.
11. equal to the sum of the opposite interior angles
13. subject and predicate
14. the length of the opposite side divided by the length of the adjacent side
16. a trigonometric function of an angle
17. having or appearing to have length,breadth,depth

1. a solid or hollow body,object or part having the shape
2. the branch of mathematics dealing with the relations of the sides and angles
3. the length of the line segment that connects the points
4. a relationship between two numbers
6. convex or star
7. a part,share of something
8. the square of the length of the hypotenuse of a right triangle equals the sum of the squares of the lengths of the other two sides
10. same shape
12. each angular point of a polygon,polyhedron,or other figure
15. the distance around something