Download Triangles! - Brookville Local Schools

Triangles can be sorted in
different ways.
 One way is by the length of their sides.
Examine, or
look closely, at
the triangles in
this picture.
What do you
notice about
the length of
the sides of the
triangles?
There are three ways:
 1)
 2)
 3)
Let’s build triangles!
 Take out the pieces from your bag. Use
same-color straws to make three different
kinds of triangles.
 Discuss properties of the triangles with
your table.
End day 1
Draw a
red line
around
the
perimeter
of the
equilateral
triangles
in this
picture.
All
sides are
the same
length.
Start day 2
Draw a
blue line
around
the
perimeter
of the
isosceles
triangles
in this
picture.
2 sides
are the
same
length.
Start day 2
Draw a
green line
around
the
perimeter
of the
scalene
triangles
in this
picture.
No sides are
the same
length.
Start day 2
There are three ways to
classify by length of sides:
All
sides are
the same
length.
2 sides
are the
same
length.
No sides are
the same
length.
There is another way to
classify triangles…
What do you
think it could
be?
You can also classify triangles by
the measures of their angles.
There are three ways!
 1)
 2)
 3)
Let’s make triangles!
Triangle #1• Fold your square paper diagonally in half.
• Unfold. Cut on the fold to make two
triangles.
• Mark the 90 degree angle with a square in
the corner.
• Label triangle.
Let’s make triangles!
Triangle #2• Choose one of the two remaining pieces of
paper.
• Draw an obtuse angle.
• Draw a third line to make a triangle.
• Cut out your triangle.
• Label triangle.
Let’s make triangles!
Triangle #3• On the last piece of paper, draw a triangle
with ALL acute angles.
• Cut out your triangle.
• Label triangle.
Glue your triangles onto your
poster. Label your poster.
White board activity:
 Draw an isosceles obtuse triangle.
White board activity:
 Draw an equilateral acute triangle.
White board activity:
 Draw a scalene right triangle.
Homework: Homework
16.5