Problem Overview:
The task involves solving problems related to the
Angle Addition Postulate and the
Angle Bisector Theorem. The worksheet is designed for a partner activity, where Partner A and Partner B are working together to solve geometric problems involving angles.
Key Concepts:
1.
Angle Addition Postulate: If a point lies in the interior of an angle, then the measure of the whole angle is equal to the sum of the measures of the two smaller angles formed.
- Mathematically: If point \( D \) lies in the interior of \( \angle ABC \), then \( m\angle ABD + m\angle DBC = m\angle ABC \).
2.
Angle Bisector Theorem: An angle bisector divides an angle into two congruent angles.
- Mathematically: If \( BD \) bisects \( \angle ABC \), then \( m\angle ABD = m\angle DBC \).
Solution to Each Problem:
####
Problem 1:
-
Partner A: \( m\angle 1 = 30^\circ \)
-
Partner B: \( m\angle 2 = 60^\circ \)
Using the Angle Addition Postulate:
\[ m\angle 1 + m\angle 2 = m\angle ABC \]
\[ 30^\circ + 60^\circ = 90^\circ \]
So, \( m\angle ABC = 90^\circ \).
####
Problem 2:
-
Partner A: \( m\angle 1 = 45^\circ \)
-
Partner B: \( m\angle 2 = 45^\circ \)
Using the Angle Addition Postulate:
\[ m\angle 1 + m\angle 2 = m\angle ABC \]
\[ 45^\circ + 45^\circ = 90^\circ \]
So, \( m\angle ABC = 90^\circ \).
####
Problem 3:
-
Partner A: \( m\angle 1 = 70^\circ \)
-
Partner B: \( m\angle 2 = 20^\circ \)
Using the Angle Addition Postulate:
\[ m\angle 1 + m\angle 2 = m\angle ABC \]
\[ 70^\circ + 20^\circ = 90^\circ \]
So, \( m\angle ABC = 90^\circ \).
####
Problem 4:
-
Partner A: \( m\angle 1 = 50^\circ \)
-
Partner B: \( m\angle 2 = 50^\circ \)
Using the Angle Addition Postulate:
\[ m\angle 1 + m\angle 2 = m\angle ABC \]
\[ 50^\circ + 50^\circ = 100^\circ \]
So, \( m\angle ABC = 100^\circ \).
####
Problem 5:
-
Partner A: \( m\angle 1 = 60^\circ \)
-
Partner B: \( m\angle 2 = 30^\circ \)
Using the Angle Addition Postulate:
\[ m\angle 1 + m\angle 2 = m\angle ABC \]
\[ 60^\circ + 30^\circ = 90^\circ \]
So, \( m\angle ABC = 90^\circ \).
Final Answers:
1. \( m\angle ABC = 90^\circ \)
2. \( m\angle ABC = 90^\circ \)
3. \( m\angle ABC = 90^\circ \)
4. \( m\angle ABC = 100^\circ \)
5. \( m\angle ABC = 90^\circ \)
Boxed Final Answer:
\[
\boxed{90^\circ, 90^\circ, 90^\circ, 100^\circ, 90^\circ}
\]
Parent Tip: Review the logic above to help your child master the concept of angle addition worksheet.