math

4. a parallelogram with opposite equal acute angles
6. a plane figure with four straight sides and four right angles
8. the height of an object or point in relation to sea level or ground level.
12. the center point of the object.
14. the point where the triangle's three perpendicular bisectors intersect.
15. the point where all the three altitudes of the triangle cut or intersect each other.
17. An angle bisector or the bisector of an angle is a ray that divides an angle into two equal parts
18. a quadrilateral with only one pair of parallel sides.

1. line that bisects another line segment at a right angle, through the intersection point.
2. having all its sides of the same length.
3. a four-sided plane rectilinear figure with opposite sides parallel.
5. a plane figure with four equal straight sides and four right angles.
7. a quadrilateral whose four sides can be grouped into two pairs of equal-length sides that are adjacent to each other.
9. at equal distances.
10. the middle number in a sorted list of numbers
11. the intersection point of all the three interior angle bisectors of the triangle
13. two opposite corners of a square
16. having equal angles.