Geometry Final

4. Coplanar points or lines lie in the same plane. A plane is a flat surface that extends forever.
7. The circumcenter is the point where the perpendicular bisectors of a triangle meet. It is equally distant from all three vertices of the triangle.
9. A line is a straight path that extends forever in both directions. It contains infinitely many points.
10. A cylinder is a three-dimensional figure with two parallel circular bases. The bases are connected by a curved surface.
11. The centroid is the point where the three medians of a triangle intersect. It is also the triangle’s center of balance.
12. A cone is a three-dimensional figure with one circular base and one vertex. Its sides curve from the base to the vertex.
13. pair A linear pair is a pair of adjacent angles whose noncommon sides form a straight line. Their measures add up to 180°.
15. angle An acute angle is an angle that measures greater than 0° and less than 90°. Acute angles are smaller than right angles.
16. Area is the amount of space inside a two-dimensional figure. It is measured in square units.
17. Equidistant means being the same distance from two or more objects. A point can be equidistant from two endpoints of a segment.

1. angles Complementary angles are two angles whose measures add up to 90°. They do not have to be next to each other.
2. A counterexample is an example that proves a statement false. Only one counterexample is needed to disprove a conjecture.
3. A conjecture is an educated guess based on observations or patterns. It may be true or false until it is proven.
5. The incenter is the point where the angle bisectors of a triangle intersect. It is equally distant from all sides of the triangle.
6. An angle is formed by two rays that share the same endpoint. The shared endpoint is called the vertex.
7. Congruent figures have the same size and shape. Congruent angles have equal measures, and congruent segments have equal lengths.
8. Circumference is the distance around a circle. It can be found using the formulas C = \pi d or C = 2\pi r.
11. Collinear points are points that lie on the same line. Three or more points can be collinear.
14. angles Adjacent angles are two angles that share a common side and a common vertex. They are next to each other without overlapping.
16. bisector An angle bisector is a ray or segment that divides an angle into two congruent angles. Each new angle has the same measure.