McGraw Hill Glencoe Geometry, 2012
MH
McGraw Hill Glencoe Geometry, 2012 View details
Study Guide and Review
Continue to next subchapter

Exercise 20 Page 526

Compare the ratios of corresponding sides. Remember, compare the longest side with the longest side and the shortest side with the shortest side.

Are the Triangles Similar? Yes.
Similarity Statement: â–ł IJK ~ â–ł HFG
Explanantion: See solution.

Practice makes perfect

Let's review the theorems that can help us prove that two triangles are similar.

  1. AA (Angle-Angle) Similarity Postulate: If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.
  2. SSS (Side-Side-Side) Similarity Theorem: If the corresponding side lengths of two triangles are proportional, then the triangles are similar.
  3. SAS (Side-Angle-Side) Similarity Theorem: If the lengths of two sides of one triangle are proportional to the lengths of two corresponding sides of another triangle and the included angles are congruent, then the triangles are similar.
We are asked to determine whether the given triangles are similar.

Notice that we are given the lengths of all the sides in both triangles. Therefore, we can compare the ratios of the corresponding sides. To identify them we can use the side lengths. Remember, compare the longest side with the longest side and the shortest side with the shortest side.

Let's find and simplify the ratios! rccccc Longest Sides: &JK/FG & = & 6/9 & = & 2/3 [1.2em] Shortest Sides: &IJ/HF & = & 4/6 & = & 2/3 [1.2em] Remaining Sides: &KI/GH & = & 5/7.5 & = & 2/3 As we can see, all three ratios are equal. Therefore, the corresponding sides are proportional, and by the SSS Similarity Theorem, the triangles are similar. â–ł IJK ~ â–ł HFG