Across
- 5. polygon with four edges (or sides) and four vertices or corners
- 10. a regular quadrilateral, it has four equal sides and four equal angles
- 12. having all its sides of the same length
- 14. the center of the incircle of a triangle or other figure.
- 16. having two sides of equal length
- 17. an angle of exactly 90°
- 18. identical in form; coinciding exactly when superimposed.
- 19. parallelogram with four equal sides and opposite equal angles
- 20. a triangle that has three unequal sides
Down
- 1. is the line segment connecting the midpoints of two sides of a triangle
- 2. 4-sided flat shape with straight sides where all interior angles are right angles (90°).
- 3. 4-sided flat shape with straight sides where opposite sides are parallel
- 4. The point where the three "altitudes" of a triangle meet.
- 6. the angle between any side of a shape, and a line extended from the next side.
- 7. the square of the length of the hypotenuse of a right triangle equals the sum of the squares of the lengths of the other two sides.
- 8. Any of the four angles formed inside two straight lines when these lines are intersected by a third straight line.
- 9. one which is more than 90° but less than 180°
- 11. a point of concurrency of the triangle
- 13. a plane figure with at least three straight sides and angles, and typically five or more.
- 15. refers to an angle less than 90°,