Download IM1Lesson 4_3 - Aquinas High School

Lesson 4.3
Conditional Statements
“Geometry Refresher”
Right Angle = 90
Acute Angle = less than 90
Obtuse Angle = more than 90
Straight Angle = 180
Supplementary Angles = 180
Complementary Angles = 90
Polygons- a closed shape with 3 or more straight
sides
Trapezoid-
Triangle-
PentagonSquare-
HexagonRectangleHeptagonRhombus-
Octogon-
Rewrite the conditional statement:
All 180 angles are straight angles.
If-Then: If an angles measure is 180, then it is
a straight angle.
Converse: If an angle is straight, then the
measure of the angle is 180.
Inverse: If an angles measure is NOT 180,
then it is NOT a straight angle.
Contrapositive: If an angle is NOT straight,
then the measure of the angle is NOT 180.
Can you write this as a biconditional
statement?
Rewrite the conditional statement:
4x – 8 = -28, because x = -5
If-Then: If x = -5, then 4x – 8 = -28
Converse: If 4x – 8= -28, then x = -5
Inverse: If x ≠ -5, then 4x – 8 ≠ -28
Contrapositive: If 4x – 8 ≠ -28, then x ≠ -5
Can you write this as a biconditional
statement?
Rewrite the conditional statement:
All cats are mammals.
If-Then: If an animal is a cat, then it is a
mammal.
Converse: If an animal is a mammal, then it is
a cat.
Inverse: If an animal is NOT a cat, then it is
NOT a mammal.
Contrapositive: If an animal is NOT a
mammal, then it is NOT a cat.
Can you write this as a biconditional
statement?
Rewrite the conditional statement:
A midpoint bisects a segment.
If-Then: If a point on a segment is the
midpoint, the point bisects the segment.
Converse: If a point bisects a segment, then
the point is the midpoint.
Inverse: If a point on a segment is NOT the
midpoint, then the point does NOT bisect the
segment.
Contrapositive: If a point does NOT bisect the
segment, then the point is NOT the midpoint.
Can you write this as a biconditional
statement?
Rewrite the statement as a biconditional:
If two angles are supplementary, then the sum of their
measure is 180.
Converse: If the sum of two angles is 180, then the two angles
are supplementary.
Biconditional: Two angles are supplementary if and only if the
sum of their measure is 180.
Rewrite the statement as a biconditional:
If a polygon is equilateral, then all of its sides are
congruent.
Converse: If a polygons sides are all
congruent, then the polygon is equilateral.
Biconditional: A polygon is equilateral if
and only if the sides are all congruent.
Rewrite the statement as a biconditional:
If two angles are complementary, then the sum of their
angles is 90.
Converse:
Biconditional:
True or False? Explain.
B
A
C
1.
AC  CD
D
2.
ACDand BDC  90