<h2><u>Angles</u></h2><h3>If angle 1 is 140°, then find the measure of the other angles.</h3>
∠2 = <u>40°</u>
∠3 = <u>40°</u>
∠4 = <u>140°</u>
∠5 = <u>140°</u>
∠6 = <u>40°</u>
∠7 = <u>40°</u>
∠8 = <u>140°</u>
<u>Explanation:</u>
The relationship between ∠1 and ∠2 are <u>supplementary angles</u>, so when you <u>add up their measurements, it will become 180°</u>. Simply subtract 180 and 140 to get the measure of ∠2. As well as ∠3, they're <u>linear pairs</u>. And they are also <u>supplementary</u>. To determine the measure of ∠6 and ∠7, notice the <u>relationship</u> between ∠2 and ∠6. As you noticed, it is <u>corresponding angles</u>. So they <u>have the same measurement</u>. If <u>∠2 = 40°</u>, then <u>∠6 = 40°</u>. As well as ∠7, because the relationship between ∠6 and ∠7 are <u>vertical pairs</u>. So the angle measurement of ∠7 is also <u>40°</u>.
Meanwhile, the relationship between ∠1 and ∠4 are <u>vertical pairs</u>. It means they also <u>have the same measurement</u>. So ∠4 = <u>140°</u>. The relationship between ∠1 and ∠5 are <u>corresponding angles</u>, so they also <u>have the same measurement</u>. If <u>∠1 = 140°</u>, then <u>∠5 = 140°</u>. The relationship between ∠1 and ∠8 are <u>alternate exterior angles</u>, and they also <u>have the same measurement</u>. <u>If ∠1 = 140°</u>, then <u>∠8 = 140°</u>.