McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
Practice Test
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Exercise 23 Page 467

Notice that ∠ SQR is an exterior angle to △ QRT, so you can apply the Exterior Angle Theorem.

Statements
Reasons
1.
RQ bisects ∠ SRT
1.
Given
2.
∠ SRQ ≅ ∠ QRT
2.
Definition of angle bisector
3.
m∠ SRQ = m∠ QRT
3.
Definition of congruent angles
4.
∠ SQR is exterior to △ QRT
4.
From the diagram
5.
m∠ SQR > m∠ QRT
5.
Exterior Angle Theorem
6.
m∠ SQR > m∠ SRQ
6.
Substitution

Since RQ bisects ∠ SRT we have that ∠ SRQ ≅ ∠ QRT, which means that m ∠ SRQ = m ∠ QRT.

Next, we notice that ∠ SQR is an exterior angle to △ QRT.

Therefore, by applying the Exterior Angle Theorem, we have that m ∠ SQR > m ∠ QRT but, since m ∠ SRQ = m ∠ QRT, we obtain that m ∠ SQR > m ∠ SRQ.

Two-Column Proof

In the following table we summarize the proof we did before.

Statements
Reasons
1.
RQ bisects ∠ SRT
1.
Given
2.
∠ SRQ ≅ ∠ QRT
2.
Definition of angle bisector
3.
m∠ SRQ = m∠ QRT
3.
Definition of congruent angles
4.
∠ SQR is exterior to △ QRT
4.
From the diagram
5.
m∠ SQR > m∠ QRT
5.
Exterior Angle Theorem
6.
m∠ SQR > m∠ SRQ
6.
Substitution