| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
What is 3a - 7a?
| 21a | |
| -4a | |
| -4 | |
| -4a2 |
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.
3a - 7a = -4a
What is the area of a circle with a radius of 5?
| 81π | |
| 9π | |
| 5π | |
| 25π |
The formula for area is πr2:
a = πr2
a = π(52)
a = 25π
On this circle, line segment CD is the:
radius |
|
circumference |
|
chord |
|
diameter |
A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).
What is the circumference of a circle with a diameter of 16?
| 15π | |
| 5π | |
| 17π | |
| 16π |
The formula for circumference is circle diameter x π:
c = πd
c = 16π
If angle a = 24° and angle b = 35° what is the length of angle d?
| 136° | |
| 132° | |
| 156° | |
| 124° |
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° - 24° - 35° = 121°
So, d° = 35° + 121° = 156°
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° - 24° = 156°