What is the length of ? A. 13 B. 9 C. 81 D. 11

Mathematics

1 answer:

andrew-mc [135]3 years ago

6 0

Answer:

C. 81

Step-by-step explanation:

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A museum worker randomly displays 5 historical writings in a row. What is the probability that the worker lines them up from the

Mars2501 [29]

The number of ways to arrange the 5 writings in a row is 5! = 5 * 4 * 3 * 2 * 1 = 120 ways.

There is only 1 way to arrange the writings from oldest to newest.

Therefore, the probability is 1/120.

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2 years ago

There is a lightning rod on top of a building. From a location 500 feet from the base of the building, the angle of elevation to

Kitty [74]

<h2>Hello!</h2>

The answer is:

The height of the lightning rod is 27.4 feet.

To solve the problem, we need to use the given information about the two points of observation, since both are related (both finish and start at the same horizontal distance) we need to write to equations in order to establish a relationship.

So, writing the equations we have:

We know that the angle of elevation from the base of the buildings is 36°

Also, we know that from the same location, the angle of elevation to the top of the lightning rod is 38°.

Using the information we have:

To the top of the building:

$tan(\alpha )=\frac{DistanceToTheTopOfTheBuilding}{BuildingBase}\\\\tan(36\°)=\frac{DistanceToTheTopOfTheBuilding}{BuildingBase}$

To the top of the lightning rod:

$tan(\alpha )=\frac{DistanceToTheTopOfTheLightningRod}{BuildingBase}\\\\tan(38\°)=\frac{DistanceToTheTopOfTheLightningRod}{BuildingBase}$

Now, isolating we have:

$tan(36\°)=\frac{DistanceToTheTopOfTheBuilding}{BuildingBase}\\\\DistanceToTheTopOfTheBuilding=tan(36\°)*BuildingBase \\\\DistanceToTheTopOfTheBuilding=tan(36\°)*500feet=363.27feet$

Also, we have that:

$tan(38\°)=\frac{DistanceToTheTopOfTheLightningRod}{BuildingBase}\\\\DistanceToTheTopOfTheLightningRod=tan(38\°)*BuildingBase\\\\DistanceToTheTopOfTheLightningRod=tan(38\°)*500feet=390.64feet$