Geometry vocab

3. A polygon with three sides and three angles.
5. A line, segment, or ray that is perpendicular to a line segment at its midpoint, dividing it into two equal parts.
8. A line segment connecting the midpoints of two sides of a triangle, parallel to the third side.
11. A triangle with three sides of different lengths.
12. The center of a circle that passes through all the vertices of a triangle.
13. A rectangle with all sides of equal length.
16. The process of solving a system of equations by adding or subtracting the equations to eliminate one of the variables.
17. The process of replacing a variable in an expression with a given value.
18. A polygon with four sides.
19. The point where the medians of a triangle intersect, dividing each median into two segments in a 2:1 ratio.
20. The point that divides a line segment into two equal parts.
21. A quadrilateral with opposite sides parallel.

1. A line segment from a vertex of a triangle perpendicular to the opposite side.
2. The middle number in a sorted list of numbers (either ascending or descending)
4. A parallelogram with all angles of 90 degrees.
6. A parallelogram with all sides of equal length.
7. A set of two or more equations containing the same variables.
9. A triangle with at least two sides of equal length.
10. The point where two or more lines or curves intersect.
11. A value or set of values that satisfy an equation or system of equations.
14. A triangle with all three sides of equal length.
15. The point where the altitudes of a triangle intersect.