Download Equilateral triangle: A triangle with 3 sides the same length

Equilateral triangle: A triangle with 3 sides the same
length.
Isosceles triangle: A triangle with 2 sides that are the
same length.
Scalene triangle: A triangle with no sides the same
length.
Square: A quadrilateral with 4 sides the same length
and 4 angles the same measure.
***All squares are rectangles, but not all rectangles
are squares.
Rectangle: A quadrilateral with opposite sides the
same length and 4 angles of the same measure.
Parallelogram: A quadrilateral with opposite sides
the same length and opposite angles of the same
measure.
Investigation 1.2
Reflection Symmetry: two halves that are mirror
images of each other.
Line of Symmetry: A line that if a shape is folded
over this line the two halves of the shape would
match exactly.
Rotation Symmetry:
A shape has rotation symmetry if it can be rotated
less than a full turn around its center point to a
position where it looks exactly as it did before it was
rotated.
Investigation 1.3
Regular Polygon: A polygon in which all the sides
are the same length and all the angles have the same
measure.
Irregular Polygon: all sides are not the same length or
all the angles are not the same measure.
Congruent: same angles, same shape, same size.
Tiling: covering a flat surface with shapes that fit
together without any gaps or overlaps.
Investigation 2.1
Right angle: has a measure of 90 degrees. This is the
benchmark we use to help us estimate angles of other
polygons.
Investigation 2.5
Parallel Lines: Lines on a plane that never meet.
These lines are straight and extend forever in two
directions.
Transversal: A line that intersects 2 or more lines.
Ex)
Acute angle: An angle with a measure less than 90
degrees.
Obtuse angle: An angle with a measure greater than
90 degrees and less than 180 degrees.
Straight angle: An angle with a measure exactly 180
degrees.
Perpendicular: Two lines that intersect to form right
angles. Ex)
Vertex: A corner of a polygon.
Supplementary angles: angles on the same side that
work together to equal 180 degrees.
Complementary angles: angles that work together to
form 90 degrees.
Alternate interior angles: In the diagram below
angles 3 and 6 are alternate interior angles.
1
3
2
4
Vertical Angles: In the diagram above angles 1 and
4 and angles 2 and 3 are vertical angles.
Angle sum: The sum of all the measures of the
interior angles of a polygon.
Angle sum formula: 180 x (n-2)
Memorize the names of the regular polygons and
their number of sides on page 9! 