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# Trig

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1. The angle of elevation from the top of one building to another is 26 degrees. If the shorter building is 400 feet tall and buildings are 1500 feet apart, how tall is the other building?

2. A 200-foot-supporting cable is tied to the top of a cell phone tower then secured to a point on the ground. If the angle of elevation from the point on the ground to the top of the tower is 38 degrees, find the height of the tower.

3. An airplane is descending to a runaway. At an altitude of 15.2 miles, its horizontal distance to the runway is 60 miles. Find the angle of descent.

I've been stuck on these questions for a while now. I don't understand how I'm supposed to solve these. Apparently, I need to use trig but how do I use it on word problems. Please help if you can.

Oct 16, 2019

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Oct 17, 2019
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AGREE with SVS!

Try to learn from his link!

CalculatorUser  Oct 17, 2019
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1. The angle of elevation from the top of one building to another is 26 degrees. If the shorter building is 400 feet tall and buildings are 1500 feet apart, how tall is the other building?

We can use  the tangent to find this...........

tan 26°  =  (400  + h) / 1500    where (400 + h) is the height of the taller building

Multiply both sides by  1500

1500 tan 26°   =  400 + h

1500 tan 26° - 400  =  h  ≈ 331.6  ft

So   the height of the taller building  is    731.6 ft   Oct 17, 2019
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2. A 200-foot-supporting cable is tied to the top of a cell phone tower then secured to a point on the ground. If the angle of elevation from the point on the ground to the top of the tower is 38 degrees, find the height of the tower.

We know the hypotenuse of a right triangle  (200) and we are looking for the side opposite the given angle

The sine will work here ....it relates the opposite side and hypotenuse

sin 38°  = h  / 200       multiply both sides by 200

200 sin 38°  =  h   ≈  123.1 ft  =  tower height   Oct 17, 2019
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3. An airplane is descending to a runaway. At an altitude of 15.2 miles, its horizontal distance to the runway is 60 miles. Find the angle of descent.

We have a right triangle....we know the opposite side to the angle we are trying to find  (15.2)  and the adjacent side   (60)......

We can use the inverse tangent  (arctan) to find the angle

arctan ( 15.2 / 60 )  =  the angle  ≈   14.2°   Oct 17, 2019