Mathematics

1. angle that is less than 90⁰
4. the point of intersection of all the three medians of triangle
6. when the sum of two angles is equal to 90 degree
9. half of diameter
12. the opposite sides are parallel and equal to each other and all four angles are right angles
13. perimeter of a circle is called
14. part of a line with one end point
15. a triangle in which all three sides have the same length
16. number staring from 1 is called

2. who's volume is l*b*h
3. the average of the given numbers
5. a line which intersects two or more lines at distinct points
7. When none of the sides of a triangle are equal
8. a number that can be represented as the quotient p/q of two integers such that q ≠ 0
10. lines that never meet
11. a six-sided polygon