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Solution (1a):</h3>
<em>The measure of ∠4 is 115° because if we use the </em><u>180° angle property</u><em>, the </em><u>sum of ∠2 and ∠4 must be 180</u><em>, as it forms a </em><u>straight line.</u><em> Seek below to </em>know how to find <em>∠4 using the </em><u>180° angle property.</u>
<u>Reviewing the known clues:</u>
- Given: ∠2 = 65°
- To find: ∠4
<u>Using the 180° angle property:</u>
- ∠2 + ∠4 = 180 (Straight line)
- => 65 + ∠4 = 180
- => ∠4 = 180 - 65
- => ∠4 = 115°
We can conclude that the measure of <u>∠4 is 115°.</u>
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Solution (1b):</h3>
<em>There are some other ways to solve for </em><u>∠7</u><em>. However, the easiest property to use here is the </em><u>Exterior angle property.</u><em> If we use that property, we can say that </em><u>∠7 is 65°</u><em>, because </em><u>∠2 is 65°.</u><em> For proof, let's use an alternate way to prove this.</em>
<u>Reviewing the known clues:</u>
- Given: ∠2 = 65°
- To find: ∠7
<u>Using the vertically opposite angles property:</u>
- ∠2 = ∠3 = 65° (Vertically opposite angles)
<u>Using the corresponding angles property:</u>
- ∠3 = ∠7 = 65° (Corresponding angles)
- => ∠7 = 65° (Proved)
We can conclude that the measure of <u>∠7 is 65°.</u>
<h3>________________________________________________</h3><h3>Solution (1c):</h3>
<em>As said in the above solution</em>, <u>∠2 = ∠3</u> <em>is equivalent due to</em> <u>vertically opposite angles.</u> <em>To prove this, we will use the</em> <u>180° angle property.</u> <em>Seek below for proof.</em>
<u>Reviewing the known clues:</u>
- Given: ∠2 = 65°
- To find: ∠3
<u>Using the 180° angle property:</u>
- ∠2 + ∠1 = 180
- => 65 + ∠1 = 180
- => ∠1 = 180 - 65
- => ∠1 = 115°
<u>Using the 180° angle property:</u>
- ∠1 + ∠3 = 180
- => 115 + ∠3 = 180
- => ∠3 = 180 - 115
- => ∠3 = 65° (Proved)
We can conclude that the measure of <u>∠3 is 65°.</u>
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