Geometry

3. formed when two straight lines or rays meet at a common endpoint.
4. a set of collinear points are connected in a one-dimensional plane
9. distance around a circle
10. three or more points lie on a straight line
11. the number of unit squares that cover the surface
13. determined by adding the length of all the sides
15. a point where two or more curves, lines, or line segments meet or intersect

1. a^{2}+b^{2}=c^{2}
2. Two lines intersecting each other at a right angle
5. the line that passes through the center and divides the circle into two equal parts
6. All four interior angles measure 90 degrees
7. coplanar infinite straight lines that do not intersect at any point
8. identical in shape and size.
12. the ratio of the circumference of a circle to its diameter.
14. a line that starts at a single point, known as the endpoint and stretches infinitely in one direction.