Five-Minute Check (over Lesson 10–6)
Main Idea and Vocabulary
Key Concept: Similar Figures
Example 1: Identify Similar Figures
Example 2: Find Side Measures of Similar Triangles
Example 3: Real-World Example
• Determine whether figures are similar and find
a missing length in a pair of similar figures.
• Corresponding Angles: The angles of similar figures
that “match”.
• Corresponding Sides: The sides of similar figures that
“match”.
• Indirect Measurement: Uses similar figures to find the
length, width, or height of objects that are too difficult to
measure directly.
• Similar Figures: Figures that have the same shape but
not necessarily the same size.
Identify Similar Figures
Which rectangle is similar to rectangle FGHI?
Identify Similar Figures
Find the ratios of the corresponding sides to see if they
form a constant ratio.
Answer: So, rectangle ABCD is similar to rectangle
FGHI.
Which rectangle is similar to
rectangle WXYZ?
A.
C.
B.
1.
2.
3.
A
B
C
Find Side Measures of Similar Triangles
If ΔABC ~ ΔDEF, find the length of
.
Find Side Measures of Similar Triangles
Since the two triangles are similar, the ratios of their
corresponding sides are equal. So, you can write
and solve a proportion to find
.
Answer:
If ΔJKL ~ ΔMNO, find the length of
.
A. 9 in.
B. 11.5 in.
C. 13.5 in.
D. 15 in.
1.
2.
3.
4.
A
B
C
D
ARCHITECTURE A rectangular picture window
12 feet long and 6 feet wide needs to be shortened
to 9 feet in length to fit a redesigned wall. If the
architect wants the new window to be similar to the
old window, how wide will the new window be?
Answer: So, the width of the new window will be
4.5 feet.
Tom has a rectangular garden which has a length of
12 feet and a width of 8 feet. He wishes to start a
second garden which is similar to the first and will
have a width of 6 feet. Find the length of the new
garden.
A. 4 ft
B. 6 ft
C. 9 ft
D. 10 ft
1.
2.
3.
4.
A
B
C
D
End of the Lesson
Five-Minute Check (over Lesson 10–6)
Image Bank
Math Tools
Tessellations
Translations
(over Lesson 10-6)
Classify the quadrilateral using the name that best describes it.
Determine and explain whether the statement is sometimes,
always, or never true. A square is a parallelogram.
Determine and explain whether the statement is 1.
A
B
sometimes, always, or never true. A rhombus is a2. square.
3.
4.
Which of the following is not a parallelogram?
A. Sqaure
B. rectangle
C. Trapezoid
D. rhombus
C
D
(over Lesson 10-6)
Classify the quadrilateral using
the name that best describes it.
A. square
B. rectangle
C. rhombus
D. trapezoid
1.
2.
3.
4.
A
B
C
D
(over Lesson 10-6)
Classify the quadrilateral using
the name that best describes it.
A. square
B. rectangle
C. rhombus
D. trapezoid
1.
2.
3.
4.
A
B
C
D
(over Lesson 10-6)
Determine and explain whether the statement is sometimes,
always, or never true. A square is a parallelogram.
A.
B.
C.
Sometimes; parallelograms are
quadrilaterals with opposite sides
parallel and all sides are not always
congruent.
Always; parallelograms are
quadrilaterals with opposite sides
parallel and opposite sides
congruent.
Never; parallelograms are
quadrilaterals with only opposite
angles congruent. All sides are not
congruent.
1.
2.
3.
A
B
C
(over Lesson 10-6)
Determine and explain whether the statement is
sometimes, always, or never true. A rhombus is a square.
A.
B.
C.
Sometimes true; a rhombus is a
parallelogram with 4 congruent
sides. If a rhombus also has 4
right angles, it is a square.
Always true; all four sides and
angles of a rhombus are equal.
Never true; an angle of a rhombus
cannot be 90° whereas an angle
of a square is always 90°.
1.
2.
3.
A
B
C
(over Lesson 10-6)
Which of the following is not a parallelogram?
A. sqaure
B. rectangle
C. trapezoid
D. rhombus
1.
2.
3.
4.
A
B
C
D