| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
What is the circumference of a circle with a radius of 3?
| 6π | |
| 13π | |
| 26π | |
| 3π |
The formula for circumference is circle diameter x π. Circle diameter is 2 x radius:
c = πd
c = π(2 * r)
c = π(2 * 3)
c = 6π
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 |
|
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).
A cylinder with a radius (r) and a height (h) has a surface area of:
π r2h |
|
2(π r2) + 2π rh |
|
4π r2 |
|
π r2h2 |
A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r2h and the surface area is 2(π r2) + 2π rh.
If a = -2 and y = -3, what is the value of 4a(a - y)?
| -364 | |
| -8 | |
| 56 | |
| -3 |
To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
4a(a - y)
4(-2)(-2 + 3)
4(-2)(1)
(-8)(1)
-8
What is 7a8 + 6a8?
| 42a16 | |
| 13a8 | |
| a16 | |
| 42a8 |
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.
7a8 + 6a8 = 13a8