presenting
the new
lesson
A.r → t
B.If x , then y
C.If it rains , then classes
are suspended.
D.Ann will dance , if she
gets a candy.
Activity #1: Convert each
statement to if-then form, then
underline the hypothesis and
double underline the conclusion.
1. Good citizens obey rules and
regulations.
2. The sum of the measures of
complementary angles is 90◦.
3. Opposite sides of a rectangle
are parallel.
4. A quadrilateral has four sides.
5. A triangle is a polygon with
three sides.
Activity #2 Directions: Evaluate
the following statements. Use the
truth table below.
1. If a shape is a triangle, then it is
a polygon.
2. If Ana studies for her test, then
she will pass the exam.
3. If a number is even, then it is
divisible by 2.
4. If a polygon has eight sides,
then it is an octagon. 5. If a shape
is a rectangle, then it has four
sides.
1. The measure of an obtuse angle is
less than 90°.
2. All perfect-square numbers are
positive.
3. Every prime number is odd.
4. Any three points are coplanar.
Review about converting statements to the other related conditional
statements.
B.Establishin
g a
purpose
for the
lesson
Guide Question:
What have you noticed
about the hypothesis?
Conclusion?
Conditional statement is known as
if-then statements. The “if” part is the
hypothesis denoted by p, and the
“then” part is the conclusion denoted
by q.
In symbol, If p, then q.
Hypothesis tells us what is given
or what is to be assumed. Conclusion
tells us what to follow from the
assumption.
10 MIN.
Complete the table.
Statement:
Today is Tuesday, the next day is Wednesday.
C.Presenting
examples/
instances
of the
lesson
Illustrative Example:
If you get good grades,
then you will get into a good
college.
The part after the "if": you get
good grades - is called a
hypotheses and the part after the
"then" - you will get into a good
college - is called a conclusion.
A conditional statement is false if
hypothesis is true and the
conclusion is false. The example
above would be false if it said "if
you get good grades then you will
not get into a good college".
Example 2:
Given:
a: The sun is made of gas.
Example1.
Conditional Statement: If a triangle is
obtuse, then it has exactly one obtuse
angle.
Contrapositive: If a triangle has no
obtuse angle, then it is not an obtuse
triangle.
Example 2.
Conditional Statement: If two angles
are complementary, then they are
acute.
Contrapositive: If angles are not
acute, then they are not
complementary.
Example 3.
Conditional Statement: If an animal is
a cat, then it has four paws.
Analyze each statement and the truth
value of each.
Example 1.
Conditional Statement:
If it rains, then the ground is wet. (T)
Converse:
If the ground is wet, then it rained. (F)
Inverse:
If it does not rain, then the ground is
not wet.(F)
Contrapositive:
If the ground is not wet, then it did
not rain. (T)
Example 2.
Conditional Statement:
If an animal is a bird, then it has
feathers. (T)
15 MIN.
Give the equivalent statement.
1. Conditional Statement: If a triangle is obtuse, then it has exactly one obtuse
angle.
2. Conditional Statement: If two angles are complementary, then they are
acute.
3. Conditional Statement: If an animal is a cat, then it has four paws.