Across
- 5. triangle：a triangle in which two of the sides are the same length.
- 7. to show that one number or amount is added to another.
- 10. lines：two lines have the point of intersection.
- 12. number is weakened by another number.
Down
- 1. lines：two lines will never intersect.
- 2. angle：an angle between 90 and 180 degrees.
- 3. flat shape with three straight sides and three angles.
- 4. triangle：a triangle whose sides are each a different length.
- 6. 2and3
- 8. angle：an angle of 90˚, like the angles at the corners of a square.
- 9. than：smaller than.
- 11. triangle：a triangle whose three sides are all the same length.