Geometry: An Interactive Journey to Mastery

(Greg DeLong) #1

  1. PAQB is a kite.
    Recall that the diagonals of a kite are perpendicular, and one
    diagonal bisects the other. Label the lengths h, xDQGíx
    as shown in Figure S.19.9.
    We have x^2 + h^2 = 25^2 :HDOVRKDYHͼ௘íx௘ͽ^2 + h^2 = 29^2.
    That is, 36^2 íx + x^2 + h^2 = 29^2. That is, 36^2 íx + 25^2 = 29^2 ,
    \LHOGLQJíx 
    This gives x = 15.
    So, hx   252225 2 2 15 20 and AB = 2h 


Lesson 20



  1. D௘ͽ Cr    
    E௘ͽ Cr 7, 5 ; 5.
    F௘ͽ Cr  7, 1 ; 10.
    G௘ͽ Cr  25, 0 ; 1.
    H௘ͽ Cr 0, 0 ; 19.
    I௘ͽ Cr  17, 17 ; 17.
    )RUJ௘ͽDQGK௘ͽZHQHHGWRFRQGXFWVRPHDOJHEUDLFZRUNDVIROORZV
    J௘ͽ
    22
    22


21 8168116





xx yy
xy

 





Cr     
K௘ͽ
22
22

20 100 10 25 0 100


10 5 100


xx yy
xy

 





Cr 10, 5 ; 10.

A


h
h

25 29


25 29


B


P x (^36) íx Q
Figure S.19.9

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