+0  
 
0
56
1
avatar

Thanks in advance.

Guest May 7, 2018
Sort: 

1+0 Answers

 #1
avatar+86643 
+1

A. AB  is the hypotenuse of a 30-60-90 right triangle....it will be twice as long as the  side opposite the 30°  angle  = CB

 

So....AB   = 2 CB  =  2 (271)  =  542 ft

 

 

B. We need to find  AC...it will  √3  times as long as BC   = 271√3 ft

 

So...using the Law of Cosines....we have

 

AD^2  = AC^2  + DC^2  - 2 (AC) (DC) cos ( 74°)

 

AD  =  √ [  (271√3)^2  + (772)^2  - 2 (271√3)(772)cos (74°) ]  =  785.2 ft

 

 

C.  We can find angle E  as follows :

 

DC^2  = DE^2  + CE^2  - 2(DE)(CE)cos (E)

 

772^2   = 543^2 + 561^2  - 2(543)(561) cos E

 

[ 772^2  - 543^2 - 561^2 ]  /  [ -2(543)(561) ]   = cos E

 

Take the inverse cosne to find E

 

arccos  ( [ 772^2  - 543^2 - 561^2 ]  /  [ -2(543)(561) ] )  = E  = 88.7°

 

 

 

cool cool cool

CPhill  May 7, 2018

8 Online Users

avatar
New Privacy Policy (May 2018)
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  Privacy Policy