Question

Roof trusses are triangular structures that provide support to the roof of a house. The picture below shows a roof truss.



What is the length of the piece of wood required to make the side AB of the roof truss?

12 sec 45°

12 over cos ec45


12 cosec 45°

12 over sec 45

Answer 1

@hba @jim_thompson5910

Answer 2

first find BC

Answer 3

sin(45) = BC/12

BC = 12*sin(45)

Answer 4

oh wait, we can do it this way and save a ton of time

cos(angle) = adjacent/hypotenuse

cos(45) = AB/12

12*cos(45) = AB

AB = 12*cos(45)

Answer 5

so the third option?

Answer 6

cosecant corresponds to sine

Answer 7

so no, it's a bit tricky with all the "co" terms so I understand the confusion

Answer 8

ok so now what

Answer 9

@jim_thompson5910 @hba

Answer 10

AB = 12*cos(45)

AB = 12/(1/cos(45))

AB = 12/(sec(45))

Answer 11

so the first option?

Answer 12

close, but no

Answer 13

the last option

Answer 14

yes, that's it