| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.21 |
| Score | 0% | 64% |
What is the area of a circle with a radius of 4?
| 25π | |
| 3π | |
| 16π | |
| 36π |
The formula for area is πr2:
a = πr2
a = π(42)
a = 16π
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 |
|
acute, obtuse |
|
obtuse, acute |
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).
Simplify (y + 9)(y - 1)
| y2 + 10y + 9 | |
| y2 - 10y + 9 | |
| y2 - 8y - 9 | |
| y2 + 8y - 9 |
To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:
(y + 9)(y - 1)
(y x y) + (y x -1) + (9 x y) + (9 x -1)
y2 - y + 9y - 9
y2 + 8y - 9
A trapezoid is a quadrilateral with one set of __________ sides.
equal angle |
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parallel |
|
right angle |
|
equal length |
A trapezoid is a quadrilateral with one set of parallel sides.
If angle a = 30° and angle b = 43° what is the length of angle d?
| 113° | |
| 150° | |
| 156° | |
| 126° |
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° - 30° - 43° = 107°
So, d° = 43° + 107° = 150°
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° - 30° = 150°