two similar polygon have areas of 100 square inches and 81 square inches.If a side of the first is 5 in., find the corresponding
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Answer:
From top to bottom, the boxes shown are number 3, 5, 6, 2, 4, 1 when put in ascending order.
Step-by-step explanation:
It is convenient to let a calculator or spreadsheet tell you the magnitude of the sum. For a problem such as this, it is even more convenient to let the calculator give you all the answers at once.
The TI-84 image shows the calculation for a list of vectors being added to 4∠60°. The magnitudes of the sums (rounded to 2 decimal places—enough accuracy to put them in order) are ...
... ║4∠60° + 3∠120°║≈6.08
... ║4∠60° + 4.5∠135°║≈6.75
... ║4∠60° + 4∠45°║≈7.93
... ║4∠60° + 6∠210°║≈3.23
... ║4∠60° + 5∠330°║≈6.40
... ║4∠60° + 7∠240°║≈ 3
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In the calculator working, the variable D has the value π/180. It converts degrees to radians so the calculation will work properly. The abs( ) function gives the magnitude of a complex number.
On this calculator, it is convenient to treat vectors as complex numbers. Other calculators can deal with vectors directly
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<em>Doing it by hand</em>
Perhaps the most straigtforward way to add vectors is to convert them to a representation in rectangular coordinates. For some magnitude M and angle A, the rectangular coordinates are (M·cos(A), M·sin(A)). For this problem, you would convert each of the vectors in the boxes to rectangular coordinates, and add the rectangular coordinates of vector t.
For example, the first vector would be ...
3∠120° ⇒(3·cos(120°), 3·sin(120°)) ≈ (-1.500, 2.598)
Adding this to 4∠60° ⇒ (4·cos(60°), 4°sin(60°)) ≈ (2.000, 3.464) gives
... 3∠120° + 4∠60° ≈ (0.5, 6.062)
The magnitude of this is given by the Pythagorean theorem:
... M = √(0.5² +6.062²) ≈ 6.08
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<em>Using the law of cosines</em>
The law of cosines can also be used to find the magnitude of the sum. When using this method, it is often helpful to draw a diagram to help you find the angle between the vectors.
When 3∠120° is added to the end of 4∠60°, the angle between them is 120°. Then the law of cosines tells you the magnitude of the sum is ...
... M² = 4² + 3² -2·4·3·cos(120°) = 25-24·cos(120°) = 37
... M = √37 ≈ 6.08 . . . . as in the other calculations.
Answer: The area of the Polygon D is 36 times larger than the area of the Polygon C.
Step-by-step explanation:
<h3> The complete exercise is: "Polygon D is a scaled copy of Polygon C using a scale factor of 6. How many times larger is the area of Polygon D than the area Polygon C"?</h3>In order to solve this problem it is important to analize the information provided in the exercise.
You know that the Polygon D was obtained by multiplying the lengths of the Polygon C by the scale factor of 6.
Then, you can identify that the Length scale factor used is:
Now you have to find the Area scale factor.
Knowing that the Length scale factos is 6, you can say that the Area scale factor is:
Finally, evaluating, you get that this is:
Therefore, knowing the Area scale factor, you can determine that the area of the Polygon D is 36 times larger than the area of the Polygon C.