CK12 - Trigonometry

b.

9. A buildingcastsa 100-footshadow, whilea 20 foot flagpolenext to the buildingcastsa 24 foot shadow.
   How tall is the building?


10. Explainin your own wordswhatit meansfor trianglesto be similar.

Answers

1. 
   

   Either5 inchesor 7 inches.

   
   


2. 
   

   A right trianglecannotbe an obtusetriangle.If a triangleis right triangle,one anglemeasures90 degrees.
   If a triangleis obtuse,one anglemeasuresgreaterthan 90. Thereforethe sum of the two angleswouldbe
   greaterthan 180 degrees,whichis not possible.

   
   


3. 
   

   104o

   
   


4. 
   

a. The anglesum in the triangleis 180. If you subtractthe 90-degreeangle,you have180-90= 90 degrees,
whichis the sum of the remainingangles.

b. 90 - 23 = 67o

6. 
   

   7.5

   
   


7. 
   

   130o

   
   


8. 
   

a. No

b. Yes, by SSS or HL