Geometry

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Geometry
Georgia Performance Standards
Jan Munroe jmunroe_at_forsyth.k12.ga.us Sawnee
Elementary School Forsyth County Schools
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Angles
An angle is formed by 2 rays or 2 line segments
that share the same endpoint.
Angle formed by 2 segments
Angle formed by two rays
The endpoints where the rays or segments meet is
called the vertex of the angle. The rays or
segments are called the sides of the angle.
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Classifying Angles
Angles may be classified according to size. Use
the protractor tool to measure the angles below.
An accute angle measures between 0 and 90
degrees.
An obtuse angle measures between 90 and 180
degrees.
A right angle measures 90 degrees.
A reflex angle measures between 180 and 360
degrees.
A straight angle measures 180 degrees
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Now let's check for understanding. Use the
spotlight tool to identify the angles below as
the names are called. Then drag away the yellow
to reveal the answers!
An accute angle measures between 0 and 90
degrees.
An obtuse angle measures between 90 and 180
degrees.
A right angle measures 90 degrees.
A reflex angle measures between 180 and 360
degrees.
A straight angle measures 180 degrees
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Use the spotlight tool to locate the right,
acute, obtuse, reflex and straight angles in the
illustation below.
B
A
C
D
G
F
E
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Parallel and Perpendicular Lines
Perpendicular lines are lines that intersect or
cross and form right angles.
Parallel lines are lines on a flat surface that
never meet. They are always the same distance
apart.
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Triangles are the simplest type of polygons. The
prefix tri means three. Triangles have 3
vertices, 3 sides,and 3 angles.
Right Triangle
Equilateral Triangle
Has one right (90 degree angle).
All sides and angles are equal.
Scalene Triangle
Isosceles Triangle
Has no equal sides and no equal angles.
Has two equal sides and two equal angles.
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Drag the triangles at the bottom of this page to
the boxes in which they belong!
Right Triangles
Isosceles Triangles
Equilateral Triangles
Scalene Triangles
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A quadrangle is a polygon that has 4 sides.
Another name for quadrangle is quadrilateral.
The prefix "quad" means four. All quadrangles
have 4 sides, 4 vertices and 4 angles.
Rhombus
Parallelogram
Opposite corners of a square are pulled in
opposite directions.
Quadrangles with 2 pairs of parallel sides.
Rectangle
Opposite sides are equal.
Trapezoid
Square
All sides may have different lengths and angles
may be different.
Has 4 equal sides and 4 equal angles.
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Trapezoid
Parallelogram
Rectangle
Square
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Check for Understanding
____ 1. Which one of the following figures is a
trapezoid?
A.
B.
C.
____ 2. Which one of the following figures is a
right angle?
A.
B.
C.
____ 3. Which one of the following figures is a
parallelogram?
B.
A.
C.
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Check for Understanding
____ 4. Which one of the following figures is
an equilateral triangle?
A.
B.
C.
____ 5. Which one of the following figures is
an example of parallel lines?
A.
B.
C.
____ 6. Which one of the following figures is
an acute angle?
B.
A.
C.
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Use the voter button to select the correct answer.
1. A right angle measures A. 180 degrees B.
between 0 and 90 degrees C. 90 degrees
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2. A reflex angle measures A. between 180 and
360 degrees B. between 90 and 180 degrees C.
180 degrees
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3. A straight angle measures A. 90 degrees B.
between 90 and 180 degrees C. 180 degrees
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4. Acute angles measure A. between 180 and 360
degrees B. between 0 and 90 degrees C.
between 90 and 180 degrees
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Use the voter button to select the correct answer.
6. Lines or line segments that never meet and
are always the same distance apart are called
A. intersecting lines B. parallel lines C.
perpendicular lines
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7. Lines or line segments that cross and form
right angles are called A. intersecting
lines B. parallel lines C. perpendicular lines
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8. Lines or line segments that cross each other
are called A. intersecting lines B. parallel
lines C. perpendicular lines
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10. A triangle with one right angle is
called A. a scalene triangle B. an
equilaterial triangle C. a right triangle
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11. A triangle that has no equal sides is
called A. a scalene triangle B. an
equilateral triangle C. a right triangle
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Use the voter button to select the correct answer.
12. A quadrilateral that has two pairs of
parallel sides is called A. a trapezoid B.
a kite C. a parallelogram
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13. A quadrangle with 1 pair of parallel sides
and may have different lengths for all sides
is called A. a trapezoid B. a kite C. a
parallelogram
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14. Quadrangles that are parallelograms are A.
trapezoids and kites B. rectangles, rhombuses
and squares C. cubes and trapezoids
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Credits
Bell, M. (et.al.). Everyday Mathematics. The
University of Chicago School Mathematics
Project. Everyday Learning Chicago, Illinois,
2002.