The length of the shadow of a building is 120 meters, as shown below:

Question

prince1342 · Answer

attachment

prince1342 · Answer

What is the height of the building?

 325.24 m
 240 m
 120 m
 207.84 m

prince1342 · Answer

i have no idea as to how to get the height

mathstudent55 · Answer

What are you learning now? About a 30-60-90 triangle, or about sine, cosine, and tangent of a right triangle?

prince1342 · Answer

sin and cos and tan, the triangle stuff too

mathstudent55 · Answer

Ok.
Have you learned SOHCAHTOA?

prince1342 · Answer

Yep

mathstudent55 · Answer

SOHCAHTOA is a way to remember the trig ratios.

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SOH:   $\sin A = \dfrac{opp}{hyp}$

CAH:   $\cos A = \dfrac{adj}{hyp}$

TOA:   $\tan A = \dfrac{opp}{adj}$

prince1342 · Answer

Alright i understand so far

mathstudent55 · Answer

The sine, cosine, and tangent for all angles are known numbers.
They can be easily found using a calculator.

prince1342 · Answer

I'm pretty good with sin cos and tan

mathstudent55 · Answer

You are given an angle of 60 degrees.
Whichever trig function we use to solve your problem, sin 60, cos 60, and tan 60 are all known values.

mathstudent55 · Answer

Now we look at your figure.
Your triangle has sides AB, BC, and AC.
Can you tell me which two sides are legs, and which side is the hypotenuse?

mathstudent55 · Answer

Notice that we know it's a right triangle because angle C is a right angle.

prince1342 · Answer

Well we need to know the height, so the tallest side would be opposite of hypotonuse. So we use sin?

mathstudent55 · Answer

There is no side opposite the hypotenuse.
We'll get to opposite and adjacent soon, but just answer my question.
Can you name which sides are legs and which side is the hypotenuse?

mathstudent55 · Answer

In a right triangle, the sides that form the right angle are the legs. The side opposite the right angle is the hypotenuse.

ineedhelplz · Answer

207.84 or D

prince1342 · Answer

im a little lost, sorry

mathstudent55 · Answer

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prince1342 · Answer

The hypotonuse is AB

mathstudent55 · Answer

Ok. There you have your figure.
In a right triangle, there is always only 1 right angle.
The other two angles are acute angles.
The hypotenuse is opposite the right angle.
You are correct. The hypotenuse in your case is AB.

mathstudent55 · Answer

The legs are the sides that form the right angle.
In this case, the legs are AC and BC.

mathstudent55 · Answer

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