22 terms

# Topic 9 - Lines, Angles, and Shapes

Math - Topic 9
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point
is an exact location in space
line
is a straight path of points that goes on and on in two directions
plane
is an endless flat surface
parallel lines
never intersects
intersecting lines
pass through the same point
perpendicular lines
are lines that form square corners
line segment
is a part of a line with two endpoints
ray
is a part of a line that has one endpoint and continues on forever in one direction
angle
is a figure formed by two reays that have the same endpoint. Angles are given special names depending upon their size.
right angle
an angle of 90°, as in a corner of a square or at the intersection of two perpendicular straight lines
acute angle
is open less than a right angle
obtuse angle
is open more than a right angle but less than a straight angle
straight angle
forms a straight line
degrees
angles are usually measure in this units
protractor
a tool that is used to measure and draw angles
polygon
is a closed plane figure made up of line segments. Each line segment is a side.
vertex
The point where two sides meet.
Equilateral Triangle
Has 3 equal sides
Isosceles Triangle
Has 2 equal sides
Scalene Triangle
0 equal sides
acute triangle
has three acute angles. All of its angles measure less than a right angle.
obtuse triangle
has one obtuse angel. One angle has a measure greater than right angle.