Geometry puzzle

4. a quadrilateral whose four sides all have the same length.
8. a quadrilateral with reflection symmetry across a diagonal.
10. a line that bisects another line segment at a right angle, through the intersection point.
12. the centre point of the object
13. a simple quadrilateral with two pairs of parallel sides.
16. a plane figure with four equal straight sides and four right angles.
17. the intersection point of all the three interior angle bisectors of the triangle,
18. a line segment joining two vertices of a polygon or polyhedron, when those vertices are not on the same edge

1. the point of intersection between the three perpendicular bisectors of the triangle's sides,
2. a quadrilateral with four right angles
3. having all its sides of the same length.
5. the point where all three altitudes of the triangle intersect
6. having equal angles
7. being the same or equal distance
9. a line that passes through two very specific points on a triangle: a vertex, or corner of a triangle, and its opposite side at a right, or 90-degree, angle
11. a line that splits an angle into two equal angles
14. denoting or relating to a value or quantity lying at the midpoint of a frequency distribution of observed values or quantities, such that there is an equal probability of falling above or below it.
15. a quadrilateral with only one pair of parallel sides.