| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.00 |
| Score | 0% | 60% |
A cylinder with a radius (r) and a height (h) has a surface area of:
4π r2 |
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π r2h2 |
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π r2h |
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2(π r2) + 2π rh |
A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r2h and the surface area is 2(π r2) + 2π rh.
If the area of this square is 36, what is the length of one of the diagonals?
| 6\( \sqrt{2} \) | |
| 5\( \sqrt{2} \) | |
| 8\( \sqrt{2} \) | |
| 2\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{36} \) = 6
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 62 + 62
c2 = 72
c = \( \sqrt{72} \) = \( \sqrt{36 x 2} \) = \( \sqrt{36} \) \( \sqrt{2} \)
c = 6\( \sqrt{2} \)
Solve for b:
b2 + 7b - 26 = 4b + 2
| -6 or -9 | |
| 4 or -7 | |
| 2 or -2 | |
| 2 or -8 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
b2 + 7b - 26 = 4b + 2
b2 + 7b - 26 - 2 = 4b
b2 + 7b - 4b - 28 = 0
b2 + 3b - 28 = 0
Next, factor the quadratic equation:
b2 + 3b - 28 = 0
(b - 4)(b + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 4) or (b + 7) must equal zero:
If (b - 4) = 0, b must equal 4
If (b + 7) = 0, b must equal -7
So the solution is that b = 4 or -7
A trapezoid is a quadrilateral with one set of __________ sides.
right angle |
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equal length |
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parallel |
|
equal angle |
A trapezoid is a quadrilateral with one set of parallel sides.
Solve for c:
c2 - 49 = 0
| 7 or -4 | |
| 3 or -5 | |
| 7 or -7 | |
| 9 or 2 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
c2 - 49 = 0
(c - 7)(c + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c - 7) or (c + 7) must equal zero:
If (c - 7) = 0, c must equal 7
If (c + 7) = 0, c must equal -7
So the solution is that c = 7 or -7