Download Triangles

Triangles
I can differentiate between the
different types of triangles.
Created by:
Maggie Howe and Rachel Tankersley
Sycamore Elementary 5th grade
Essential Questions:
What is a triangle?
How do you classify triangles?
What is an acute triangle?
What is a right triangle?
What is an obtuse triangle?
What is an isoscelse triangle?
What is an equilateral triangle?
What is a scalene triangle?
 Triangles are everywhere.
 They can be found bracing a bridge.
 Triangles can be found racking up billiard
balls.
 Triangles can
be classified by
sides.
 OR
 Triangles can
be classified by
angles.
TRIANGLES BY SIDES
 SCALENE
 ISOSCELES
 EQUILATERAL
SCALENE TRIANGLE
 WHEN 3 PEOPLE
GET ON THE
SCALES TO SEE
HOW MUCH THEY
WEIGHT, EACH ONE
WEIGHS A
DIFFERENT
AMOUNT.
SO…………
 A scalene triangle has
no equal sides.
 All sides are different
lengths.
Isosceles Triangles
 Isosceles triangles
have 2 equal sides.
 The angles
opposite the equal
sides are also
equal. <B = <C AB
= AC
Equilateral Triangles
 All 3 sides of an
equilateral triangle are
equal.
 Each angle of an
equilateral triangle are
equal.
 Each angle must be
60 degrees.
 Now let’s review.
 What kind of triangle has all 3 sides and
angles equal?
Equilateral Triangle
 What kind of triangle has all sides a different
length ?
SCALENE TRIANGLE
 What kind of triangle has 2 equal sides?
AN ISOSCELES TRIANGLE
TRIANGLES BY ANGLES
 Acute
 Right
 Obtuse
 A right triangle has one 90 degree or
RIGHT angle.
Acute triangles
3 angles less than 90 degrees.
OBTUSE TRIANGLE
 An obtuse triangle has one obtuse angle.
What type of triangle is this?
 Use right, obtuse, or acute.
What type of triangle is this?
 Use right, obtuse, or acute.
What type of triangle is this?
 Use right, obtuse, or acute.
What type of triangle is this?
 Use right, obtuse, or acute.
What type of triangle is this?
 Use right, obtuse, or acute.
What type of triangle is this?
 Use isosceles, scalene, or equilateral.
What type of triangle is this?
 Use isosceles, scalene, or equalateral.
What type of triangle is this?
 Use isosceles, scalene, or eqilateral.
What type of triangle is this?
 Use isosceles, scalene, or equilateral.
What type of triangle is this?
 Use isosceles, scalene, or equilateral.
Which one of these is labeled
incorrectly?
Right Triangle
Equilateral Triangle
Scalene Triangle
Follow Up
Draw an acute triangle.
Draw a right triangle.
Draw an obtuse triangle.
Draw an isoscelse triangle.
Draw an equilateral triangle.
Draw a scalene triangle.
Answer the following questions:
Can you have an acute, scalene triangle?
Can you have a right isoscelese triangle?
32
Can you have an obtuse, equilateral triangle?