Mathematics

3. when the sum of two angles is equal to 90 degree
4. half of diameter
7. the average of the given numbers
8. part of a line with one end point
9. the opposite sides are parallel and equal to each other and all four angles are right angles
11. When none of the sides of a triangle are equal
13. perimeter of a circle is called
14. number staring from 1 is called
15. a six-sided polygon

1. who's volume is l*b*h
2. a line which intersects two or more lines at distinct points
5. lines that never meet
6. a triangle in which all three sides have the same length
9. a number that can be represented as the quotient p/q of two integers such that q ≠ 0
10. the point of intersection of all the three medians of triangle
12. angle that is less than 90⁰