Unit 4 Vocabulary

5. Two figures are said to be similar if they are the same shape.
8. is the center of a triangle's circumcircle.
11. Two triangles are congruent if their corresponding sides are equal in length, and their corresponding angles are equal in measure.
13. the incircle or inscribed circle of a triangle is the largest circle contained in the triangle; it touches the three sides.
15. the center of the incircle of a triangle or other figure.
16. the point through which all the mass of a triangular plate seems to act.
17. A line, segment, or ray that passes through a midpoint of another segment is
18. a set of objects if the distances between that point and each object in the set are equal.

1. The perpendicular bisector of a side of a triangle is a line perpendicular to the side and passing through its midpoint.
2. A line segment that connects two midpoints of the sides of a triangle is
3. A line which cuts a line segment into two equal parts at 90°.
4. The base angles of an isosceles triangle are the angles formed by the base and one leg of the triangle.
6. A segment from a vertex of the triangle, perpendicular to the side opposite that vertex of the triangle.
7. The point where the three "altitudes" of a triangle meet.
9. are geometric figures that have the same shape and size.
10. is a line segment drawn from a vertex to the midpoint of the opposite side of the vertex.
12. tells us that two known angles of two triangles can be congruent.
14. A line or ray that divides an angle into two congruent angles.