The ﬁgure shows a rhombus whose sides are
73.2 cm long. The angle θ is 31◦. Find the distance from A to B.
Answer in units of cm

Question

The ﬁgure shows a rhombus whose sides are
73.2 cm long. The angle θ is 31◦. Find the distance from A to B.
Answer in units of cm

anonymous · Answer

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theeric · Answer

So, you're probably starting to work with trigonometry functions, right?

anonymous · Answer

I guess, this is one question of my summer assignment so we are going to learn about this when returning to school

theeric · Answer

Oh. That's weird! But okay! Was there a packet to learn from? Well, is this for your first physics course?

theeric · Answer

I guess it must be, actually. So have you ever seen things like$$cos(\theta)$$$$sin(\theta)$$or$$tan(\theta)$$?

anonymous · Answer

The packet has just general equations the question are on an account online.

anonymous · Answer

Yup I have

theeric · Answer

I see! Have you learned how to use them?

anonymous · Answer

Yea a bit but haven't used them for awhile so I'm confused now

anonymous · Answer

Is there a certain equation to follow ?

theeric · Answer

Oh! I'll teach you, it shouldn't take long! But I'll need a moment first. I'll be right back.

anonymous · Answer

Alright thanks a ton!

theeric · Answer

My pleasure! I hope my information can help! 

So $sin(\theta)$, $cos(\theta)$ and $tan(\theta)$ are functions. They're just like any other function, but you don't need to know how they work. They're magic, and the calculator will do the work for you if you know how to use them.

|dw:1375310719611:dw|They're useful only for right triangles, meaning triangles that have a right angle in them.

anonymous · Answer

attachment

theeric · Answer

There's a phrase that's designed to help you remember what they are used for, which is what you should care about.
SOH CAH TOA
S is for $sin(\theta)$, C is for $cos(\theta)$, and T is for $tan(\theta)$. As for the others, they're
O: opposite side
H: hypotenuse (longest side, opposite of the right angle)
A: adjacent side

They work like this. Look at SOH.
It means $sin(\theta)=\Large\frac{O}{H}\normalsize =\Large\frac{\text{opposite side}}{\text{hypotenuse}}$

theeric · Answer

The trigonometric functions will give you the ratio between two sides of a right triangle. We mostly use them rearranged, though. That is,$$H \times sin(\theta)=O$$And, $$H\times cos(\theta)=A$$

theeric · Answer

|dw:1375311499341:dw||dw:1375311596847:dw|So you want to find the opposite side from theta. You know the hypotenuse and the angle, and that's all you need to know. That, and how to use $sin(\theta)$.

(The hypotenuse is the length of the side.)