Polygons
What is a polygon?
Any closed, 2 dimensioal shape with 3 or more straight sides and angles
How do we categorize triangles?
Angles and sides
What is a quadrilateral?
It is a 2 dimensional shape with 4 sides, 4 corners, 4 angles.
What is the equation for area?
Length x width
What is the equation for perimeter?
Length + Length + Width +Width
Add all sides together.
Are quadrilaterals polygons? Why?
Yes, because they are 2 dimensional, closed figures with 3 or more straight lines.
What is a triangle?
A shape with 3 sides, 3 angles and 3 vertices.
What does parallel mean?
2 lines that run side by side that are always the same distance apart. They never meet and never cross.
What is the area of a square that has a dimension of 7 in?
49in2
How would you find perimeter of a square with 5in?
20in
Which shapes are not polygons? Why?
circles, because they have curved lines.
What are the angles in triangles? What do they each measure?
Acute- less than 90 degrees
Obtuse- Any angle from 90 degrees to 180 degrees
Right- 90 degree angle
Straight Line- 180 degrees
What is a parallelogram?
A 2 dimensional, 4 sided shape with opposite sides equal. 2 pair of parallel lines.
What is the area of a rectangle with dimensions of 6in and 5in?
30in2
18in
Name 4 polygon categories.
Triangle, pentagon, hexagon, octagon
What are the 3 categories for triangle sides? Describe them.
scalene- all sides different length
isosceles- 2 sides have the same length
equilateral- all 3 sides have the same length
Why is a trapezoid not a parallelogram?
It is not a parallelogram because it only has 1 set of parallel lines.
How can you find the area of a composite shape?
Break the shape apart and find the area of each smaller shape then add together.
What does perimeter measure?
It measures all around the edge of the shape.
Can a polygon have 2 sides? Why?
No, a 2 sided shape will have curves.
What are the three categories of triangle angles? Describe them.
Right triangle- 90 degree angle
Obtuse triangle- 1 angle greater than 90 degrees
Acute triangle- all angles less than 90 degress
Which shape can be a parallelogram, rectangle and a rhombus?
Square
How can you find the area if a dimension is missing?
You can use what we know about squares, rectangles and other shapes and fill in the missing dimensions.
You find the missing dimensions by using the attributes of shapes.