| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.07 |
| Score | 0% | 61% |
The formula for the area of a circle is which of the following?
c = π d |
|
c = π r |
|
c = π d2 |
|
c = π r2 |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.
If a = 5, b = 6, c = 9, and d = 4, what is the perimeter of this quadrilateral?
| 17 | |
| 24 | |
| 16 | |
| 10 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 5 + 6 + 9 + 4
p = 24
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
supplementary, vertical |
|
vertical, supplementary |
|
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).
What is 3a8 - 9a8?
| 12a16 | |
| -6a8 | |
| -6 | |
| 12 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
3a8 - 9a8 = -6a8
If side a = 9, side b = 4, what is the length of the hypotenuse of this right triangle?
| \( \sqrt{13} \) | |
| \( \sqrt{82} \) | |
| \( \sqrt{53} \) | |
| \( \sqrt{97} \) |
According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:
c2 = a2 + b2
c2 = 92 + 42
c2 = 81 + 16
c2 = 97
c = \( \sqrt{97} \)