What are the relationship among the
lengths of the sides of rectangle
ABCD on the right?
Because all sides of a rectangle are equal, then it is
called a square.
Now try to find square objects around you.
What are you going to
To define a square
To discover the formula
of the perimeter and
area of a square
Do this with your partner
Materials: paper, scissors, a ruler and a protractor
1. Draw rectangle ABCD with AB=BC=CD=AD=5 cm
as shown in the figure on the right.
2. Draw the diagonals of the rectangle ABCD and
mark the intersection of the diagonals, then name it
3. Use a protractor to measure the angles below.
4. What are the measures of ∠AOB, ∠BOC, ∠COD, and ∠DOA?
5. What are the measures of ∠OAD, ∠OBA, ∠OCB, and ∠ODC?
6. What are the measures of ∠OAB, ∠OBC, ∠OCD, and ∠ODA?
7. Based on the above activity, what can you conclude? Explain it.
Mini - Lab
Critical Thinking 1. What are the measures of ∠BAC and ∠BCA?
2. What are the measures of ∠DBA and ∠ADB?
Mathematics for Junior High School Year 7 / 311
The properties of a square:
1. The opposite sides are parallel.
2. All of the angles are right angles.
3. The diagonals are equal and bisect each other.
4. All the sides are equal.
5. The diagonals bisect the angles.
6. The diagonals cross perpendicularly.
Based on those properties, we can say that a square is a
rectangle with 4 equal sides.
PROBLEM 9 Are all properties of a rectangle also owned by a
square? Explain. Can it be in the vice versa?
PROBLEM 10 The figure on the left is square PQRS.
a. List 3 segments equal to PQ .
b. List 3 segments equal t