Question

What is the length of the part BC of the bridge?

Answer 1

\[Cos \theta= \frac{adjacent \ side }{Hypotenuse}\]
Can you try ?

Answer 2

Yeah I was hoping someone would give me a guide rather than a answer. Looking at the problem now

Answer 3

\[\text {Adjacent side is the side adjacent to the angle here its BC}\]

Answer 4

so 1600/cos 30deg?

Answer 5

Nope
\[Cos \theta= \frac{adjacent \ side }{Hypotenuse} \]We have to find adjacent side here
\[\text{Adjacent side} = Cos\theta \times Hypotenuse \]

Answer 6

And you must know these common values
http://cemca.org/ciet/Trigonometry/images/trig__mfc751a1.jpg

Answer 7

\[\text{did you understand how i got }\]\[\text{Adjacent side} = Cos\theta \times Hypotenuse\]

Answer 8

No, not at all actually. I dont understand half of any of this. I wasnt in class for half of the year and they just put me in here without any knowledge of geo.

Answer 9

Ok when we are given one of the sides of a triangle and an angle then you can find the other side using Trigonometric values like Sin,Cos,tan etc

Answer 10

Yeah, but what do Sin,Cos and Tan equal ?

Answer 11

\[\sin \theta= \frac{opposite \ side}{Hypotenuse}\]\[\cos \theta= \frac{adjacent \ side}{Hypotenuse}\]\[\tan \theta= \frac{sin\theta}{cos\theta }= \frac{opposite \ side}{adjacent \ side}\] \[Cosec \theta= \frac{1}{\sin \theta}=\frac{Hypotenuse}{Opposite \ side}\]\[Sec \theta= \frac{1}{\cos \theta}= \frac{Hypotenuse}{adjacent \ side}\]\[Cot \theta= \frac{1}{\tan \theta}= \frac{adjacent \ side }{opposite \ side }\]

Answer 12

http://www.mathsisfun.com/sine-cosine-tangent.html
this might help you as well :)

Answer 13

Sohcahtoa
an easy way to remember which side to divide by which..

Soh "S"ine = "O"pposite / "H"ypotenuse
cah "C"osine = "A"djacent / "H"ypotenuse
toa "T"angent = "O"pposite / "A"djacent


And you must learn these common values
http://cemca.org/ciet/Trigonometry/images/trig__mfc751a1.jpg

Answer 14

\[\text{Now you know }\]\[Cos \theta= \frac{adjacent \ side }{Hypotenuse}\]
So how do you find adjacent side ?

Answer 15

If\(\large \ x=\frac{a}{b}\)
then how do you find \(a\)?
we mulltiply both sides by \(b\)
\(\large xb=a\)




same way\[Cos \theta= \frac{adjacent \ side }{Hypotenuse}\]

So\[\text{Adjacent side} = Cos\theta \times Hypotenuse\]


here
\(\theta=30^o\)\[hypotenuse=1600m\]\[\cos 30^o=\frac{\sqrt{3}}{2}\] Now can you find ?

Answer 16

(sorry i was picking up my sister from day-care) and No i still dont understand it.

Answer 17

Its ok