GEOMETRY

1. a polygon with four equal sides and four right angles. Area= a^2
4. Trigonometric ratio. Formula= p/h
6. the length of a straight line through the centre of a circle. formula=2r
8. a quantity obtained by the addition of a group of numbers. Ex 3+7
9. a point equidistant from the ends of a line or the extremities of a figure. Has a theorem based on it.
10. a parallelogram with four right angles. Area= lb
11. An angle less than 90 degrees but more than 0 degrees, all angles of equilateral are of this kind.
12. a triangle that contains an obtuse interior angle. Ex △ABC in which ∠A= 100degree,∠B= 40degree,∠C=40degree
13. a continuous portion of a circle of two types minor and major.
14. a quadrilateral whose opposite sides are parallel and equal. formula of area = bh
17. the extent of a 2-dimensional surface enclosed within a boundary.Ex 6a^2
18. being everywhere equidistant and not intersecting. Opposite lines are like this in a parallelogram.
19. two angles whose sum is a right angle.For example, a 50-degree angle and a 40-degree angle.
20. A plane figure, area= ∏r^2

2. elevation above sea level or above the earth's surface.All triangles have three of this.
3. an area that is in the middle of some larger region. It is found in a circle.
5. The length of the closed curve of a circle. formula= 2∏r
7. a four-sided polygon. Ex rectangle
15. All sides of this triangle are equal. Each angle is 60degree
16. a line enclosing a plane area. Ex 2(l+b)