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anonymous

  • one year ago

what are the values of a and b?

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  1. anonymous
    • one year ago
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  2. welshfella
    • one year ago
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    use the property of similar triangles - their corresponding sides are in the same ratio

  3. welshfella
    • one year ago
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    the large triangle and the smaller one containing the sides a and b are similar

  4. anonymous
    • one year ago
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    So a would be 18?

  5. welshfella
    • one year ago
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    how did you get that?

  6. Directrix
    • one year ago
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    The triangles are similar by the AA Postulate. It appears to me that we are missing a third numerical measure that is needed to solve the problem. @Mikayla_Rose Is the outer, large triangle given to be a right triangle? |dw:1444254138067:dw|

  7. welshfella
    • one year ago
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    you find the corresponding sides by looking at the equal angles - then use the sides opposite these angles.

  8. anonymous
    • one year ago
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    nevermind i think its 8 because that is simplifed form of 32

  9. welshfella
    • one year ago
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    yes @directrix - I have assumed that that !

  10. Directrix
    • one year ago
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    I'd like to see the equation(s) you two are using. I am not seeing it. Yes, if that angle I mentioned is a right angle, the problem can be solved. But, to assume that it is a right angle is incorrect. Of course, the diagrams in these posted problems are frequently incomplete.

  11. welshfella
    • one year ago
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    I agree we should not really assume its a right angle but I cant see how we can solve this unless we make that assumption

  12. anonymous
    • one year ago
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    I dont know how to get the answer, that is why i posted this question to get instructions.

  13. welshfella
    • one year ago
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    can you see why (assuming the big triangle is right angled whay the 2 triangles are similar - similar triangles have all 3 angles equal

  14. Directrix
    • one year ago
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    We can't give instructions when the diagram is incomplete.

  15. anonymous
    • one year ago
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    ok.... How do i complete the diagram?

  16. welshfella
    • one year ago
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    it will be complete if the big triangle has been marked as right-angled.

  17. welshfella
    • one year ago
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    - as in directrix's drawing.

  18. welshfella
    • one year ago
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    do you see what i mean?

  19. welshfella
    • one year ago
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    |dw:1444254684623:dw|

  20. welshfella
    • one year ago
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    |dw:1444254814673:dw|

  21. welshfella
    • one year ago
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    |dw:1444254888518:dw|

  22. anonymous
    • one year ago
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    okay what is the next step?

  23. welshfella
    • one year ago
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    triangles ADC and BDC are similar ( by AA postulate) therefore we can write 2 / b = b / (32+2) 2 / b = b / 34 solve for b

  24. welshfella
    • one year ago
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    can you find b?

  25. anonymous
    • one year ago
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    im working on it right now

  26. anonymous
    • one year ago
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    b= 2 sqr root 17, -2 sqr root 17

  27. welshfella
    • one year ago
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    well it has to be the positive value , of course now you can find the value of a by applying the pythagoras theorem to the small triangle.

  28. welshfella
    • one year ago
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    a^2 = (2 sqrt17)^2 - 2^2

  29. welshfella
    • one year ago
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    ok?

  30. anonymous
    • one year ago
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    i got a= sqr root 30?

  31. welshfella
    • one year ago
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    Oh - i just realised - angle ADC must be a right-angle because the 2 angles marked are equal and angle C is common.

  32. welshfella
    • one year ago
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    No a^2 = 68 - 4 = 64 a = 8

  33. anonymous
    • one year ago
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    oh okay i got it thanks a whole lot for helping me!

  34. welshfella
    • one year ago
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    yw

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