| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.66 |
| Score | 0% | 53% |
If the area of this square is 4, what is the length of one of the diagonals?
| 3\( \sqrt{2} \) | |
| 6\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 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 = \( \sqrt{a} \) = \( \sqrt{4} \) = 2
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 = 22 + 22
c2 = 8
c = \( \sqrt{8} \) = \( \sqrt{4 x 2} \) = \( \sqrt{4} \) \( \sqrt{2} \)
c = 2\( \sqrt{2} \)
Find the value of c:
-7c + y = -8
3c - 4y = -4
| -\(\frac{25}{28}\) | |
| -1\(\frac{24}{35}\) | |
| \(\frac{3}{8}\) | |
| 1\(\frac{11}{25}\) |
You need to find the value of c so solve the first equation in terms of y:
-7c + y = -8
y = -8 + 7c
then substitute the result (-8 - -7c) into the second equation:
3c - 4(-8 + 7c) = -4
3c + (-4 x -8) + (-4 x 7c) = -4
3c + 32 - 28c = -4
3c - 28c = -4 - 32
-25c = -36
c = \( \frac{-36}{-25} \)
c = 1\(\frac{11}{25}\)
Which of the following statements about a parallelogram is not true?
the area of a parallelogram is base x height |
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the perimeter of a parallelogram is the sum of the lengths of all sides |
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a parallelogram is a quadrilateral |
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opposite sides and adjacent angles are equal |
A parallelogram is a quadrilateral with two sets of parallel sides. Opposite sides (a = c, b = d) and angles (red = red, blue = blue) are equal. The area of a parallelogram is base x height and the perimeter is the sum of the lengths of all sides (a + b + c + d).
The dimensions of this trapezoid are a = 4, b = 8, c = 5, d = 2, and h = 2. What is the area?
| 25\(\frac{1}{2}\) | |
| 14 | |
| 10 | |
| 18 |
The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:
a = ½(b + d)(h)
a = ½(8 + 2)(2)
a = ½(10)(2)
a = ½(20) = \( \frac{20}{2} \)
a = 10
Factor y2 - 36
| (y + 6)(y + 6) | |
| (y + 6)(y - 6) | |
| (y - 6)(y - 6) | |
| (y - 6)(y + 6) |
To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -36 as well and sum (Inside, Outside) to equal 0. For this problem, those two numbers are -6 and 6. Then, plug these into a set of binomials using the square root of the First variable (y2):
y2 - 36
y2 + (-6 + 6)y + (-6 x 6)
(y - 6)(y + 6)