| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.17 |
| Score | 0% | 63% |
If angle a = 41° and angle b = 26° what is the length of angle d?
| 139° | |
| 136° | |
| 115° | |
| 129° |
An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:
d° = b° + c°
To find angle c, remember that the sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 41° - 26° = 113°
So, d° = 26° + 113° = 139°
A shortcut to get this answer is to remember that angles around a line add up to 180°:
a° + d° = 180°
d° = 180° - a°
d° = 180° - 41° = 139°
A trapezoid is a quadrilateral with one set of __________ sides.
equal angle |
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parallel |
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equal length |
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right angle |
A trapezoid is a quadrilateral with one set of parallel sides.
If a = c = 2, b = d = 6, and the blue angle = 59°, what is the area of this parallelogram?
| 6 | |
| 10 | |
| 12 | |
| 16 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 2 x 6
a = 12
Breaking apart a quadratic expression into a pair of binomials is called:
squaring |
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deconstructing |
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factoring |
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normalizing |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
Solve for x:
x2 + 5x - 2 = 5x - 1
| 9 or -3 | |
| 1 or -1 | |
| 7 or -3 | |
| 6 or -9 |
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:
x2 + 5x - 2 = 5x - 1
x2 + 5x - 2 + 1 = 5x
x2 + 5x - 5x - 1 = 0
x2 - 1 = 0
Next, factor the quadratic equation:
x2 - 1 = 0
(x - 1)(x + 1) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x - 1) or (x + 1) must equal zero:
If (x - 1) = 0, x must equal 1
If (x + 1) = 0, x must equal -1
So the solution is that x = 1 or -1