Download chapter 5 definitions - Flushing Community Schools

Chapter 5 Definitions
This will be worth 30 points at the end of the
chapter!
5.1
1.) Angle—A shape that is made by 2 rays that have a common endpoint.
2.) Right angle—an angle that measures 90 degrees.
3.) Acute angle—an angle that measures less than 90 degrees.
4.) Obtuse angle—an angle that measures more than 90 degrees.
5.) Straight angle—an angle that measures exactly 180 degrees.
6.) Complementary angles—2 angles that add up to 90 degrees.
7.) Supplementary angles—2 angles that add up to 180 degrees.
8.) Adjacent angles—2 angles that share a common ray.
9.) Vertical angles—2 angles that are equal in measurement and opposite of each
other when two lines intersect.
10.) Congruent angles—2 angles that are equal in measurement.
5.2
11.) Parallel lines – lines in a plane that never intersect.
12.) Perpendicular lines – lines in a plane that intersect and form 90 degree
angles.
13.) Transversal – a line that intersects two or more lines that lie in the same
plane.
14.) Alternate Interior Angles – Two angles that are on opposite sides of the
transversal and inside parallel lines. They are equal.
15.) Alternate Exterior Angles – Two angles that are on opposite sides of the
transversal and outside the parallel lines. They are equal.
16.) Corresponding Angles – Two angles that are in the same place just in
different spots. They are equal.
5.3
17.) Triangle Sum Theorem – The angle measures of a triangle add to 180
degrees.
18.) Acute triangle – A triangle that has 3 acute angles.
19.) Right triangle – A triangle that has 1 right angle.
20.) Obtuse triangle – A triangle that has 1 obtuse angle.
21.) Equilateral triangle – A triangle that has 3 congruent sides and 3 congruent
angles.
22.) Isosceles triangle – A triangle that has 2 congruent sides and 2 congruent
angles.
23.) Scalene triangle – A triangle that has no congruent sides or angles.
24.) Triangle Inequality Theorem – the sum of the lengths of any two sides of a
triangle is greater than the length of the third side.
5.4
25.) Midpoint – the point of a segment that divides the segment into 2 congruent
pieces.
(
𝑥1 + 𝑥2
2
,
𝑦1 + 𝑦2
2
)
5.5
26.) Correspondence – a way to match up 2 sets of objects.
27.) Congruent Figures – figures that have the same size and the same shape; all
corresponding sides and angles are congruent.
5.6
28.) Transformation – a change in a figure’s position or size.
29.) Translation – when a figure slides along a straight line without turning.
(x,y)
( x + # , y + #)
30.) Reflection – when a figure flips across a line to create a mirror image.
Reflect across the Y-AXIS ( x , y )
( -x , y)
Reflect across the X-AXIS ( x , y)
( x , -y)
31.) Rotation – when a figure turns around a point.
Rotate 900 clockwise
(x,y)
( y , -x)
Rotate 900 Counterclockwise ( x , y )
Rotate 1800
(x,y)
( -y , x)
(-x , -y)
32.) Dilation—The transformation that changes the size of a figure. Both
coordinates get multiplied by the same number.
(x,y)
(2x, 2y) or ( x , y )
1
1
2
2
( x, y)
5.7
33.) Similarity Transformations – transformations that result in an image that is
the same shape as the original, but a different size.
34.) Congruence Transformations – transformations that result in an image that
is the same shape and the same size as the original.