Polygons Flashcards
Formula for counting the sum of the angles in a n-sided polygon
(n - 2)*180
How much more degrees in the sum of the angles has every next polygon?
180 (triangle - 180, quadrilateral - 360, pentagon - 540, hexagon - 720)
Number of angles and sum of angles in a triangle
3, 180
Number of angles and sum of angles in a quadrilateral
4, 360
Number of angles and sum of angles in a pentagon
5, 540
Number of angles and sum of angles in a hexagon
6, 720
Number of angles and sum of angles in an octagon
8, 1020
a segment connecting two non-adjacent vertices
diagonal
Properties of a regular polygon
equilateral (all sides are equal);
equiangular (all angles are equal)
Name of a 3-side polygon
triangle
Name of a 4-side polygon
quadrilateral
Name of a 5-side polygon
pentagon
Name of a 6-side polygon
hexagon
Name of a 8-side polygon
octagon
4 Properties of a parallelogram
- opposite sides are parallel;
- opposite sides are equal;
- opposite angles are equal;
- diagonals bisect each other.
If one of them is true - all of them are true!
Area of a parallelogram
Area = base*height
Types of quadrilaterals
Parallelogram, trapezoid
Special types of parallelograms
rhombuses, rectangles, squares
2 Special properties of rhombuses
- all four sides are equal;
- diagonals are perpendicular.
2 Special properties of rectangles
- all the angles are 90;
- diagonals are congruent.
Names of the sides of trapezoid
Parallel sides are called bases and others are called legs.
Properties of trapezoid
Properties:
- has one pair of parallel sides;
- the two angles on a leg are supplementary
Area of a trapezoid
Area = avg base*height
