Download Learning Target:

Learning Target:
I can…
Describe types of and existence of triangles
Types of Triangles
Equilateral Triangle
Isosceles Triangle
Scalene Triangle
All sides are
equal
2 sides are
equal
No sides
are equal
Which statement is always true about an
equilateral triangle?
A. It has 3 congruent angles.
B. It has 1 right angle.
C. It has exactly 2 congruent sides
D. The sum of any 2 angles is 180°
Right Triangle
Has one right
angle
Acute Triangle
Has all acute
angles
Obtuse Triangle
Has one obtuse
angle
What type of triangle is shown?
A. Acute
B. Right
C. Obtuse
D. Straight
You try it!
What would you name this triangle?
a.
b.
c.
d.
Right isosceles triangle
Right scalene triangle
Right equilateral triangle
Acute scalene triangle
You try it!
What would you name this
triangle?
a.
b.
c.
d.
Right isosceles triangle
Acute isosceles triangle
Acute equilateral triangle
Obtuse scalene triangle
a.
b.
c.
d.
Right isosceles triangle
Acute isosceles triangle
Obtuse Isosceles triangle
Obtuse scalene triangle
A triangle has the conditions given below.
What type of triangle will this make?
Side Lengths: 6, 9, 10
Angles: 30°, 60°, 90°
A.
B.
C.
D.
Right scalene triangle
Right isosceles triangle
Acute scalene triangle
No triangle
A triangle has one angle that measures 58° and
one angle that measures 32°. What kind of
triangle is it?
A.
B.
C.
D.
Isosceles
Right
Obtuse
Equilateral
How many triangles exist with the given angle
measures?
80°, 50°, 50°
A. More than one triangle
B. One unique triangle
C. No triangle
Triangle Side Lengths
Any side of a triangle is always
________________than the ___________ of
the other two sides.
http://www.mathopenref.com/triangleinequalit
y.html
Example 1
Could a triangle have side lengths of:
Side 1: 4
Side 2: 8
Side 3: 2
Tests:
1) __________
2) __________
3) __________
Example 2
Could a triangle have side lengths of:
Side 1: 3
Side 2: 4
Side 3: 5
Tests:
1) __________
2) __________
3) __________
Clicker Practice
A triangle can have which of the following sets
of sides?
A. 15, 25, 45
B. 4, 12, 18
C. 1, 10, 20
D. 6, 9, 14
3)
4) Two sides of an isosceles triangle
measure 3 and 7. Which of the
following could be the measure of the
third side ?
A. 9
B. 7
C. 3
D. 12
5) Is it possible to draw a triangle with a 90˚ angle
and one leg that is 4 inches long and one leg that
is 3 inches long?
If so, draw one. Is there more than one such
triangle?
6) Jenna is drawing a blueprint of the stage for
the school show. The stage will be in the
shape of a triangle. Two sides of the triangle
measure 12 and 15 feet respectively. What is
the range of the whole-number lengths for
the third side of the triangle?
A) Side 1 + Side 2 > Side 3
B) Side 2 + Side 3 > Side 1
C) Side 1 + Side 3 > Side 2
3 ft < side 3 < 27 ft
Two sides of a triangle have the following
measures:
7, 5
Find the range of possible whole number
measures for the third side.
A. 5≤Side 3≤12
B. 2 ≤ Side 3 ≤ 12
C. 3 ≤ Side 3 ≤ 11
D. 3 ≤ Side 3 ≤ 12
Serena is drawing a blueprint of the stage
for the school show. The stage will be in
the shape of a triangle. Two sides of the
triangle measure 9 and 16 feet respectively.
What is the range of the whole-number
lengths for the third side of the triangle?
A. Between 7 and 25
B. Between 7 and 24
C. Between 8 and 24
D. Between 8 and 25
EXIT
Write the range of possible distances from the
school to the park.
Learning Target:
I can…
Construct triangles and quadrilaterals based on
given conditions
EXAMPLE
Construct an equilateral triangle with sides of 5.
Does this result in a unique triangle, more than
one triangle, or no triangle?
Construct a triangle with sides of 3 and 5.
Does this result in a unique triangle, more than
one triangle, or no triangle?
Construct a triangle with sides of 2, 5, and 9.
Does this result in a unique triangle, more than
one triangle, or no triangle?
Construct an isosceles triangle with two angles
of 45°.
Does this result in a unique triangle, more than
one triangle, or no triangle?
Quadrilaterals
EXIT
How many triangles exist with the given angle
measures?
40°, 50°, 90°
A. More than one triangle
B. One unique triangle
C. No triangle