45 Geometry Riddles

1. I have a flat top and bottom face. I have no vertices.

I am a cylinder!


2. I am a path of points continuing forever in both directions.

I am a line!


3. No matter how many sides I have, my sides are all the same length, and my angles are all the same measurement.

I am a regular polygon!

4.I am not a closed figure, so therefore…

I am NOT a polygon!

5. I am an angle with a measurement of less than 90 degrees.

I am an acute angle!

6. I am two figures of the same shape, but different size.

I am similar figures!

7. I divide a shape so that both sides look like mirror images.

I am a line of symmetry!

8. I am line segments that meet to form right angles.

I am perpendicular line segments!

9. I am a line segment that goes all the way across a circle, through its center.

I am a diameter!

10. I am a four-sided polygon.

I am a quadrilateral!

11. I am a five-sided polygon.

I am a pentagon!

12. I am a triangle with 3 sides of different lengths.

I am a scalene triangle!

13. I am a special kind of quadrilateral that has 2 pair of parallel sides.

I am a parallelogram!

14. I am the number of degrees in a triangle.

I am 180 degrees!

15. I am a triangle with 3 congruent sides.

I am an equilateral triangle!

16. I am a 3-D figure. All of my faces are quadrilaterals. My length is longer than my width and height.

I am a rectangular prism!

17. I am 2 angles that together create a 90 degree angle.

I am complementary angles.

18. I am a line segment from the circle to its center.

I am a radius!

19. I am a straight path of points that extend forever in one direction, and I have one endpoint.

I am a ray!

20. I am an angle with a measurement of 90 degrees.

I am a right angle!

21. I am the number of degrees in a quadrilateral.

I am 360 degrees!

22. I am the point where the 2 rays of an angle meet or the point where 2 edges of a cube meet.

I am a vertex!

23. I am the number you start at when measuring an angle with a protractor.

I am zero!

24. I am a quadrilateral with only 1 pair of parallel sides.

I am a trapezoid!

25. I am 2 shapes that are the same shape and size.

I am congruent figures!

26. I am the movement of a shape that consists of moving left, right, up, or down.

I am a slide or translation!

27. I am a transformation that is a pivot at one point.

I am a turn or rotation!

28. I am a path of points with 2 endpoints.

I am a line segment.

29. I am the distance around a circle.

I am the circumference!

30. I am lines that go in the same direction and therefore never meet.

I am parallel lines!

31. I am a quadrilateral with all 4 sides congruent. I do not have to have 90 degree angles, but I have 2 pair of parallel sides.

I am a rhombus!

32. I am a triangle with all angles measuring less than 90 degrees.

I am an acute triangle!

33. I am a triangle with all 3 sides different lengths.

I am a scalene triangle!

34. I am lines that cross each other.

I am intersecting lines!

35. I am a line segment connecting 2 points on a circle.

I am a chord!

36. I am a 3-D figure with 6 faces. All 6 faces are congruent, and the lengths of all my edges are congruent.

I am a cube!

37. I am 2 angles that combine to create a 180 degree angle.

I am supplementary angles!

38. I am an 8-sided polygon.

I am an octagon!

39. I am a triangle with 1 angle measuring more than 90 degrees.

I am an obtuse triangle!

40. I am a 3-D figure with 4 triangular faces that meet at one point.

I am a square pyramid!

41. I am also called a flip.

I am a reflection or mirror image.

42. I am a triangle with 1 angle measuring 90 degrees.

I am a right triangle!

43. I am a six-sided polygon.

I am a hexagon!

44. I am a curve between 2 points on a circle. (I am less than a semi-circle.)

I am an arc!

45.I am a 10-sided polygon.

I am a decagon!