Download Geometry - Hamilton Local Schools

Geometry!!!
Point: is a dot, named
by one letter. Ex:
A
Line: contains points,
extends in both
directions and never
ends! You name a line
with a lower case
letter. Or you can use
the capital letter
names of two points on
the line. Ex: line m, RS
or SR
R
S
m
Line segment: a part of
a line. It has a
beginning and an end.
Ex:
YZ or ZY
Y
Z
Ray: Is a part of a line
and extends in only
one direction. The
name always starts
with the endpoint. Ex:
WX
W
X
Angle: formed by two
rays that share a vertex.
A
exterior
B
C
interior
What point is the vertex?
Example:
What is the name of this
figure?
T
S
Ask yourself… what features
does the figure have?
 Has an endpoint
 Continues in one direction
It must be a ray, so… ST
Parallel: Lines that extend in
the same directions and
NEVER intersect. Ex: line b
is parallel to line c
b
c
Perpendicular: Lines that
cross each other at right
angles. Ex: line d is
perpendicular to line e
d
e
Examples:
1) Which line is
perpendicular to p?
p
q
r
2) How is a line segment
different from a line?
3) What is not a name for
this figure?
a) GH
b) Gh
c) HG
d) Line segment GH
4) What is true about
parallel lines?
Sum of angles:
The sum of interior angles of
any triangle is 180 degrees.
Example:
What is the missing angle
measure in this triangle?
?
55
55 + 80 = X
180 – X =
80
degrees
You can use this knowledge to find
the sum of the interior angles of a
quadrilateral. Look at the
quadrilateral below, ABCD. A line
segment can be drawn to connect
points A and C to make two
triangles.
A
B
D
C
The sum of angles in a triangle = 180
degrees. Since there are two
triangles in a quadrilateral, the sum
of angles if 2 times 180!! Or 360
degrees!
Example: What is the measure of
angle B in the quadrilateral above if
A = 95, C = 60, and D = 80?
Add up angles we know:
95 + 80 + 60 = Y
360 – Y =
.
Examples:
1)
Could these be the four
interior angles of a
quadrilateral: 45, 45, 90,
90?
2)
What is the missing angle
in this triangle?
?
110
40
3)
What is the missing angle
measure in this
quadrilateral?
?
80
100
130
Nets:
Many 3D (dimensional) figures can
be unfolded to form nets. A Net is a
2D shape made from the faces and
surfaces that make up a 3D figure.
Example: The diagram below
shows a net for which 3D figure?
Volume: A measure of
the number of cubic
units needed to fill the
space inside an object.
It is the amount of
space inside a solid
figure. To find the
volume of a rectangular
prism use this formula:
V = l x w x h
Ex: What is the volume
of this rectangular
prism?
3cm
2cm
4cm
Surface Area: A measure
of the number of square
units needed to cover
the outside of a figure.