Page 28 - Math Course 3 (Book 2)

Properties of Squares and Rhombi
Mo. 7

Lesson 5 THEOREMS

Examples
7.15 The diagonals of a
KEY CONCEPTS: rhombus are
perpendicular AC ▱ BD
1. Recognize and apply the properties of
rhombi.
2. Recognize and apply the properties of 7.16 If the diagonals of
parallelogram are
squares. perpendicular, then
the parallelogram is a If BD ▱ AC then
▱ABCD is a
rhombus. rhombus
(Converse of
MO. 7 - L5a Theorem 7.15)

Recognizing the Properties of 7.17 Each diagonal of a ∠DAC ≅ ∠BAC ≅
Rectangles rhombus of a bisects ∠DCA ≅ ∠BCA
a pair of opposite
angles. ∠ABD ≅ ∠CBD ≅
∠ADB ≅ ∠CDB
Vocabulary A-Z B

Let us learn some vocabulary
A

rhombus C
A four-sided quadrilateral where all sides are
congruent (have equal length). Also opposite D
sides are parallel and opposite angles are equal.

B CONCEPT SUMMARY
a
Properties of Rhombi and Squares
d1
A C Rhombi Squares

d2 1. A rhombus has all the 1. A square has all the
properties of properties of
parallelogram. parallelogram
2. A square has all the
2. All sides are properties of a
D congruent. rectangle.
3. A square has all the
3. Diagonals are
B perpendicular. properties of a
rhombus

4. Diagonals bisect the
angles of the rhombus.
A

5. Diagonals bisect the
angles of the rhombus.
C

D

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