| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.62 |
| Score | 0% | 52% |
The dimensions of this cylinder are height (h) = 9 and radius (r) = 7. What is the surface area?
| 42π | |
| 224π | |
| 144π | |
| 60π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(72) + 2π(7 x 9)
sa = 2π(49) + 2π(63)
sa = (2 x 49)π + (2 x 63)π
sa = 98π + 126π
sa = 224π
A cylinder with a radius (r) and a height (h) has a surface area of:
π r2h2 |
|
2(π r2) + 2π rh |
|
4π r2 |
|
π r2h |
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 side a = 9, side b = 3, what is the length of the hypotenuse of this right triangle?
| \( \sqrt{90} \) | |
| \( \sqrt{20} \) | |
| \( \sqrt{97} \) | |
| \( \sqrt{68} \) |
According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:
c2 = a2 + b2
c2 = 92 + 32
c2 = 81 + 9
c2 = 90
c = \( \sqrt{90} \)
If angle a = 34° and angle b = 38° what is the length of angle d?
| 138° | |
| 129° | |
| 146° | |
| 150° |
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° - 34° - 38° = 108°
So, d° = 38° + 108° = 146°
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° - 34° = 146°
The endpoints of this line segment are at (-2, -4) and (2, 6). What is the slope-intercept equation for this line?
| y = 2\(\frac{1}{2}\)x + 1 | |
| y = 1\(\frac{1}{2}\)x - 3 | |
| y = -\(\frac{1}{2}\)x + 4 | |
| y = x + 1 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is 1. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, -4) and (2, 6) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(6.0) - (-4.0)}{(2) - (-2)} \) = \( \frac{10}{4} \)Plugging these values into the slope-intercept equation:
y = 2\(\frac{1}{2}\)x + 1