Includes types and characteristics of quadrilaterals and how to solve its unknown parts.

1. Prepared by: Carlo Gabay
Carlos Punay Jr.
Junjun Lubos

2. Objectives :
I can identify the different quadrilaterals.
I can differentiate the quadrilaterals based
from there classification
I can solve the missing side and angle of a
quadrilateral.

3. Quadrilaterals
Kinds of Quadrilaterals
Square
Rectangle
Rhombus
Parallelogram
Isosceles Trapezoid
Kite

4. Square
- has 4 equal sides
- all angles are right
- diagonals are
congruent and
perpendicular
Quadrilaterals

5. Rectangle
- 2 opposite sides
are congruent
- all angles are
right
- diagonals are
congruent
Quadrilaterals

6. Rhombus
- 4 sides are equal
- 2 opposite angles are
congruent
- 2 consecutive angles
are supplementary
- diagonals are
congruent and
perpendicular
Quadrilaterals

7. Parallelogram
- 2 opposite sides are
equal
- 2 opposite angles are
congruent
- 2 consecutive angles
are supplementary
- diagonals are
congruent and
perpendicular
Quadrilaterals

8. Isosceles Trapezoid
- one pair side are parallel
- one pair side are
congruent
- base angles are
congruent
- diagonals are congruent
Quadrilaterals

9. Kite
- 2 pair sides are
congruent
- 1 pair of opposite
angle is congruent
- diagonals are
perpendicular
Quadrilaterals

11.  Example 1
Find the
dimensions of the
parallelogram
LOVE in meters.
Computation of Unknown Angles/Sides
of Quadrilaterals

12. Solution:
LO≅EV LE≅OV
4x-10=2x 4x-7=3x-4
4x-2x=10 4x-3x=7-4
x=5 x=3
LO=4x-10 LE=4x-7
=4(5)-10 =4(3)-7
=10m =5m
Therefore, the dimensions of the parallelogram LOVE are
5m by 10m.
Computation of Unknown Angles/Sides
of Quadrilaterals

13.  Example 2
What is the smaller
angle in the given
Isosceles
Trapezoid?
Computation of Unknown Angles/Sides
of Quadrilaterals

14. Solution:
(3y+3)+(6y-12)=180
3y+3+6y-12 =180
9y=180+12-3
9y=189
y=21
Computation of Unknown Angles/Sides
of Quadrilaterals

15. Substitute the value of y; y=21
(3y+3) ° (6y-12) °
= [3(21)+3]° = [6(21)-12] °
= 66° = 114°
Therefore, the smaller angle is 66°.
Computation of Unknown Angles/Sides
of Quadrilaterals

16.  Example 3
The perimeter of a rectangle is 26cm. If its width
is 3 less than its length, what are its dimension?
Solution:
P=2L+2W 4L=26+6
26=2L+2W(L-3) 4L=32
26=2L+2L-6 L=8cm
26=4L-6
Computation of Unknown Angles/Sides
of Quadrilaterals

17. Substitute the value of L to get the width;
L=8cm
W=L-3
W=8-3
W=5cm
Therefore, the dimensions of the
rectangle are 5cm by 8cm.
Computation of Unknown Angles/Sides
of Quadrilaterals

18. Checking:
L=8 , W=5
P= 2L+2W
26= 2(8)+2(5)
26= 16+10
26=26
Computation of Unknown Angles/Sides
of Quadrilaterals

19. Directions: Read the questions carefully. Write
the letter of the best answer in your answer
sheet.
1. Which statement below expresses truism?
A. Quadrilateral is compose of 5 sides..
B. Rectangle can be considered as square.
C. Square can be considered as rectangle.
D. The diagonals of a square are not
congruent.
Evaluation

20. 2. Which is one is not belong to the group?
A. square
B. rhombus
C. circle
D. kite
Evaluation

21. 3. A type of quadrilateral that has 4 equal
sides and its all angles measures 90 °.
A. Rhombus
B. Square
C. Rectangle
D. Kite
Evaluation

22. 4. What is the perimeter of the rectangle if it
measures 5 cm on its width and 2 cm on
its length?
A. 14 cm
B. 15 cm
C. 16 cm
D. 17 cm
Evaluation

23. 5. what is the area of the square if one side
measures 3 cm?
A. 6 cm2
B. 9 cm2
C. 12 cm2
D. 15 cm2
Evaluation

24. Mathematics Learner’s Material 9, pp. 297-304
Reference: