Understanding Similar Triangles
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Beginner
Start here! Easy to understand
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Beginner Explanation
Key Definitions:
• Similar triangles have all corresponding angles equal.
• Their corresponding sides are proportional by a constant scale factor.
Worked Example:
Triangle A has sides 3, 4, 5. Triangle B is similar with scale factor 2, so its sides are 6, 8, 10. You find each side by multiplying by 2, the ratio of any side in B to the corresponding side in A.
Check Yourself: If triangle C has sides 5, 12, 13 and is similar to triangle D with scale factor 3, what are the side lengths of D?
Practice Problems
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1
Quick Quiz
Single Choice Quiz
Beginner
If $\triangle ABC \sim \triangle DEF$ and $AB = 6$, $BC = 8$, $AC = 10$, $DE = 3$, find $EF$.
Please select an answer for all 1 questions before checking your answers. 1 question remaining.
2
Real-World Problem
Question Exercise
Intermediate
Teenager Scenario
A tree casts a shadow of $15$ meters while a $1.5$ meter tall person nearby casts a shadow of $3$ meters. How tall is the tree?
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3
Thinking Challenge
Thinking Exercise
Intermediate
Think About This
The triangles $\triangle PQR \sim \triangle STU$ are similar. If $PR = 9$, $QR = 12$, and $ST = 6$, find $SU$.
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4
Challenge Quiz
Single Choice Quiz
Advanced
Given $\triangle ABC \sim \triangle DEF$, where $AB = 8$, $BC = 6$, $CA = 10$, and $DE = 16$, find $EF$.
Please select an answer for all 1 questions before checking your answers. 1 question remaining.
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