Similar Triangles: Identify Matching Pairs and Calculate Their Ratio

Triangle Similarity with Ratio Calculations

In these figures, there is a pair of similar triangles and a triangle that is not similar to the others.

Determine which are similar and calculate their their similarity ratio.

888444666101010666888444222333AAABBBCCCGGGHHHIIIDDDEEEFFFABC

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

In these figures, there is a pair of similar triangles and a triangle that is not similar to the others.

Determine which are similar and calculate their their similarity ratio.

888444666101010666888444222333AAABBBCCCGGGHHHIIIDDDEEEFFFABC

2

Step-by-step solution

To solve this problem, we'll compare the side ratios of the given triangles to determine which pair are similar and find the similarity ratio.

  • Step 1: Identify the given triangle side lengths:
    Triangle A: Sides of length 88, 44, and 66.
    Triangle B: Sides of length 1010, 66, and 88.
    Triangle C: Sides of length 44, 22, and 33.
  • Step 2: Compare the ratios of corresponding sides between pairs of triangles.

Comparing Triangle A and Triangle B:

  • Ratio 810=0.8 \frac{8}{10} = 0.8 ; 460.67 \frac{4}{6} \approx 0.67 ; 68=0.75 \frac{6}{8} = 0.75

Here, the ratios are not equal; hence, triangles A and B are not similar.

Comparing Triangle A and Triangle C:

  • Ratio 84=2 \frac{8}{4} = 2 ; 42=2 \frac{4}{2} = 2 ; 63=2 \frac{6}{3} = 2

All ratios are equal, so triangles A and C are similar, with a similarity ratio of 2.

Comparing Triangle B and Triangle C:

  • Ratio 104=2.5 \frac{10}{4} = 2.5 ; 62=3 \frac{6}{2} = 3 ; 832.67 \frac{8}{3} \approx 2.67

The ratios are not equal, so triangles B and C are not similar.

Therefore, the similar triangles are Triangle A and Triangle C, with a similarity ratio of 2.

The correct answer is A + C are similar with a ratio of 2.

3

Final Answer

A + C are similar with a ratio of 2

Key Points to Remember

Essential concepts to master this topic
  • Rule: Similar triangles have all corresponding sides in same ratio
  • Technique: Calculate ratios like 84=2 \frac{8}{4} = 2 , 63=2 \frac{6}{3} = 2 , 42=2 \frac{4}{2} = 2
  • Check: All three ratios must be identical for triangles to be similar ✓

Common Mistakes

Avoid these frequent errors
  • Comparing sides in wrong order
    Don't match sides randomly like comparing 8 to 6 or 4 to 10 = wrong ratios! This leads to incorrect conclusions about similarity. Always arrange sides in order (shortest to longest) and compare corresponding positions systematically.

Practice Quiz

Test your knowledge with interactive questions

Is the similarity ratio between the three triangles equal to one?

FAQ

Everything you need to know about this question

How do I know which sides correspond to each other?

+

Start by ordering the sides from shortest to longest in each triangle. Then compare the shortest sides together, middle sides together, and longest sides together.

What if two ratios are equal but the third is different?

+

The triangles are not similar! For triangles to be similar, all three ratios must be exactly equal. Even one different ratio means they're not similar.

Can the similarity ratio be a decimal or fraction?

+

Yes! The ratio can be any positive number. For example, if sides are in ratio 32=1.5 \frac{3}{2} = 1.5 , that's a valid similarity ratio.

What if I get ratios like 2, 0.5, and 2 for three triangles?

+

Check if any ratios are reciprocals! Here, 2 and 0.5 are reciprocals, which might mean you compared the triangles in reverse order. Try flipping one comparison.

Why do we need exactly three equal ratios?

+

A triangle has three sides, so we need three ratios to be equal. This ensures that one triangle is a scaled version of the other with no distortion.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Similar Triangles and Polygons questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations