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anonymous

  • one year ago

IF triangle ABC and triangle PQR are similar triangles, find QR and PR QR= PR=

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  1. anonymous
    • one year ago
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    |dw:1436545434224:dw|

  2. mathstudent55
    • one year ago
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    Since the triangles are similar, corresponding sides have proportional lengths. First, you need to find a pair of sides, one side in triangle ABC and one side in triangle PQR, that are corresponding sides and that you know both lengths.

  3. mathstudent55
    • one year ago
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    Can you name such a pair of sides?

  4. anonymous
    • one year ago
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    IDK

  5. mathstudent55
    • one year ago
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    The way similar triangles are named tells you which sides are corresponding sides. |dw:1436546032187:dw|

  6. mathstudent55
    • one year ago
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    |dw:1436546082939:dw|

  7. anonymous
    • one year ago
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    A/B=P/Q

  8. mathstudent55
    • one year ago
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    We have the lengths of both sides AB and PQ. |dw:1436546118626:dw|

  9. anonymous
    • one year ago
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    ok

  10. mathstudent55
    • one year ago
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    |dw:1436546158422:dw|

  11. anonymous
    • one year ago
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    so how do i find QR AND PR

  12. mathstudent55
    • one year ago
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    We have the length of side BC, and we are looking for the length of side QR. We can set up a proportion: \(\dfrac{AB}{PQ} = \dfrac{BC}{QR} \) Now we fill in all the lengths we know: \(\dfrac{15}{18} = \dfrac{25}{x} \) We can cross multiply and solve for x. x is the length of side QR.

  13. mathstudent55
    • one year ago
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    \(15x = 25 \times 18\) \(15x = 450\) \(x = 30\) Since x = QR, we now have QR = 30

  14. mathstudent55
    • one year ago
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    Now we do a similar proportion to find PR.

  15. mathstudent55
    • one year ago
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    |dw:1436546418171:dw|