| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.90 |
| Score | 0% | 58% |
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
vertical, supplementary |
|
supplementary, vertical |
|
obtuse, acute |
|
acute, obtuse |
Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).
The dimensions of this trapezoid are a = 4, b = 5, c = 5, d = 8, and h = 3. What is the area?
| 26 | |
| 22 | |
| 19\(\frac{1}{2}\) | |
| 30 |
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(5 + 8)(3)
a = ½(13)(3)
a = ½(39) = \( \frac{39}{2} \)
a = 19\(\frac{1}{2}\)
What is the area of a circle with a radius of 3?
| 6π | |
| 9π | |
| 25π | |
| 7π |
The formula for area is πr2:
a = πr2
a = π(32)
a = 9π
The dimensions of this cylinder are height (h) = 5 and radius (r) = 6. What is the volume?
| 180π | |
| 196π | |
| 448π | |
| 392π |
The volume of a cylinder is πr2h:
v = πr2h
v = π(62 x 5)
v = 180π
Solve for x:
x2 + 10x + 46 = -4x + 1
| -5 or -9 | |
| 9 or -4 | |
| 2 or -6 | |
| 3 or 3 |
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 + 10x + 46 = -4x + 1
x2 + 10x + 46 - 1 = -4x
x2 + 10x + 4x + 45 = 0
x2 + 14x + 45 = 0
Next, factor the quadratic equation:
x2 + 14x + 45 = 0
(x + 5)(x + 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 5) or (x + 9) must equal zero:
If (x + 5) = 0, x must equal -5
If (x + 9) = 0, x must equal -9
So the solution is that x = -5 or -9