Question

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

Answer 1

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

My answer: 10 cos 45degrees

Answer 2

BC/AB = cos 45°, Therefore BC = AB * cos 45° - Your result is correct. :-) Well done.

Answer 3

Thanks :)

Answer 4

Oh, I'm very sorry. Just discovered an error of mine: BC/AB = TAN 45°... So the correct answer would be BC = AB * tan 45°.

Answer 5

cos would be the opposite divided by the hypotenuse (i.e. the longest side) which we do know nothing about here. tan is the opposite (BC) divided by the adjacent (AB).

Answer 6

Oh alright. Thanks for the double check!! Very much appreciated.

Answer 7

You're very welcome.

Answer 8

tan(theta) = opposite/adjacent


tan(45) = BC/AB


tan(45) = BC/10


10*tan(45) = BC


BC = 10*tan(45)


BC = 10*1


BC = 10


Note: if you're required to have the trig function in the answer, then the answer is BC = 10*tan(45)