Download Lesson 11 Similar Triangles

Lesson 11-1
Exit Ticket
Similar Triangles
Opening routine
Unit 2:
Similarity, Proof and
Trigonometry
Lesson 11 Similar Triangles
Objective: Use congruence and similarity criteria
for triangles to solve problems and to prove
relationships in geometric figures.
Essential Question: How do you use proportions
to find side lengths of similar triangles?
Lesson 11 Similar Triangles
Vocabulary
Proportion: Is the name that is given to
a statement that two ratios are equal.
In a proportion the cross products
are equal.
Similar triangles: Triangles are similar when they
preserve angle measures.
Similar triangles: Corresponding side lengths in
similar triangles are proportional.
Lesson 11 Similar Triangles
Vocabulary
Scale factor: Is the ratio between corresponding
sides of similar triangles.
Angle–Angle Similarity (AA) Theorem: If two
angles of one triangle are congruent to two
angles of another triangle, then the two
triangles are similar.
Lesson 11 Similar Triangles
Vocabulary
Side–Side–Side Similarity (SSS) Theorem: If the
corresponding side lengths of two triangles are
proportional, then the triangles are similar.
Side–Angle–Side Similarity (SAS) Theorem: If
two sides of one triangle have lengths that are
proportional to two sides of another triangle
and the included angles of those sides are
congruent, then the triangles are similar.
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Lesson 11 Similar Triangles
Guided Practice – WE DO
Lesson 11 Similar Triangles
Independent Practice – YOU DO
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Question 1 page 94
Question 2 page 94
Question 1 page 94
Question 4 page 94
Question 5 page 94
Question 6 page 94
Lesson 11 Similar Triangles
Independent Practice – YOU DO
Lesson 11 Similar Triangles
Independent Practice – YOU DO
Lesson 11 Similar Triangles
Independent Practice – YOU DO
Lesson 11 Similar Triangles
Re-teach MAFS.912.G-CO.1.3: Given a rectangle,
parallelogram, trapezoid, or regular polygon, describe the
rotations and reflections that carry it onto itself.
11. Rectangle STUV is graphed
on the coordinate plane below.
Which series of transformations
carries rectangle STUV onto
itself?
Lesson 11 Similar Triangles
11. Rectangle STUV is graphed
on the coordinate plane below.
Which series of transformations
carries rectangle STUV onto
itself?
A. reflection over the y-axis,
rotation around the origin 180o
clockwise, reflection over the
y-axis
False
Lesson 11 Similar Triangles
11. Rectangle STUV is graphed
on the coordinate plane below.
Which series of transformations
carries rectangle STUV onto
itself?
B. reflection over the x-axis,
reflection over the y-axis,
rotation around the origin 270o
counterclockwise
False
Lesson 11 Similar Triangles
11. Rectangle STUV is graphed
on the coordinate plane below.
Which series of transformations
carries rectangle STUV onto
itself?
C. reflection over the y-axis,
reflection over the x-axis,
rotation around the origin 180o
counterclockwise
True
Lesson 11 Similar Triangles
Re-teach MAFS.912.G-CO.2.6: Use geometric descriptions of rigid
motions to transform figures and to predict the effect of a given rigid
motion on a given figure; given two figures, use the definition of
congruence in terms of rigid motions to decide if they are congruent.
8. Which sequence of rigid motions would move DEF so it
completely covers D'E'F'?
A. reflection of DEF
across a vertical line
followed by a
translation to the right.
False
Lesson 11 Similar Triangles
Re-teach MAFS.912.G-CO.2.6: Use geometric descriptions of rigid
motions to transform figures and to predict the effect of a given rigid
motion on a given figure; given two figures, use the definition of
congruence in terms of rigid motions to decide if they are congruent.
8. Which sequence of rigid motions would move DEF so it
completely covers D'E'F'?
B. reflection of DEF across
a vertical line followed
by a translation down.
False
Lesson 11 Similar Triangles
Re-teach MAFS.912.G-CO.2.6: Use geometric descriptions of rigid
motions to transform figures and to predict the effect of a given rigid
motion on a given figure; given two figures, use the definition of
congruence in terms of rigid motions to decide if they are congruent.
8. Which sequence of rigid motions would move DEF so it
completely covers D'E'F'?
C. 90o clockwise rotation
of DEF about the point E
followed by a translation
down.
False
Lesson 11 Similar Triangles
Re-teach MAFS.912.G-CO.2.6: Use geometric descriptions of rigid
motions to transform figures and to predict the effect of a given rigid
motion on a given figure; given two figures, use the definition of
congruence in terms of rigid motions to decide if they are congruent.
8. Which sequence of rigid motions would move DEF so it
completely covers D'E'F'?
D. 90o clockwise rotation
of DEF about the
point F followed
by a translation
to the right.
True
Lesson 11 Similar Triangles
Closure
Essential Question: How do you use
proportions to find side lengths of
similar triangles?
Lesson 11 Similar Triangles
Homework
Geometric Constructions Packet
Due Wednesday November 2, 2016