Glencoe Math: Course 3, Volume 2
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Glencoe Math: Course 3, Volume 2 View details
5. Similar Triangles and Indirect Measurement
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Exercise 1 Page 557

If two triangles are similar, then their corresponding angles are congruent.

Not similar

Practice makes perfect

We are asked to determine whether the given triangles are similar.

From the picture, we can see that the angles Q and V have the same measure. This means that they are congruent angles. ∠ Q ≅ ∠ V

Now, we have to find the measure of the third angle in either of the two triangles to determine whether they are similar. Let's consider triangle RQS.

We know that the sum of the measures of the interior of a triangle is always 180^(∘). This lets us write an equation to find m∠ R. 47+68+ m ∠ R =180 Let's solve this equation for m ∠ R.
47+68+ m ∠ R =180
Solve for m ∠ R
115+ m ∠ R =180
115+ m ∠ R -115 = 180-115
m ∠ R =65
The measure of ∠ R is 65 ^(∘). Let's mark it on the picture.

We can see that only one pair of angles is congruent. This means that by the rule for Angle-Angle (AA) Similarity these triangles are not similar.