Vocabulary
Acute
An angle that is between 0° & 90°
Right
An angle that is exactly 90°
Obtuse
An angle that is greater than 90° but less than 180°
Reflex
An angle that is greater than 180° up to 360°
Point
is a location. It has no size (i.e. no width, no length, and no depth)
Ray
has one endpoint and goes on forever in one direction.
Line Segment
have two endpoints.
Line
could continue going in either direction forever.
Parallell
Two lines that never touch no matter how far you extend them
Perpendicular
two lines which meet at a right angle
Intersecting
two lines which cross at one point
Vertex
point at which two lines meet
Protractor
an instrument for measuring angles
45°
an angle measuring 45° of a circle
1/4, 1/2, 3/4 Turns
Complementary Angles
two angles with the sum of 90 degrees.
Supplementary Angles
two angles with a sum of 180 degrees
Symmetry
an object is symmetrical when one half is a mirror image of the other half
Triangle
a three sided polygon with three angles
Right Triangle
contains one right angle
Acute Triangle
has all three angles less than a right angle (90°)
Obtuse Triangle
one angle greater than a right angle (90)°
Isosceles Triangle
has two sides the same length
Equilateral Triangle
all its sides the same length and each of its angles are the same length
Scalene Triangle
No sides the same length and all its angles are a different measure
