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ABCD is a rectangle.  Find the length of AB.

 

 Dec 28, 2020
 #1
avatar+1162 
+2

AB = 4 * cos-1(3/4) = 3.2

 Dec 28, 2020
 #2
avatar+117546 
+1

Let   FI  =  3    IH  = 4    FH   = 5     EG  = height of rectangle  = AB

 

sin IFH   = 4/5   =sin EFG

 

sin EFG / EG  =  sin G  / 4

 

(4/5) / EG  =sin 90 / 4

 

(4/5)/ EG  = 1/ 4

 

EG  = (4/5)  /(1/4)  =  16/5   =  AB 

 

 

cool cool cool

 Dec 28, 2020
edited by CPhill  Dec 28, 2020
edited by CPhill  Dec 28, 2020

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