| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.73 |
| Score | 0% | 55% |
The formula for the area of a circle is which of the following?
a = π d2 |
|
a = π d |
|
a = π r |
|
a = 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 angle a = 29° and angle b = 48° what is the length of angle d?
| 125° | |
| 151° | |
| 149° | |
| 158° |
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° - 29° - 48° = 103°
So, d° = 48° + 103° = 151°
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° - 29° = 151°
On this circle, line segment CD is the:
radius |
|
circumference |
|
diameter |
|
chord |
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).
The endpoints of this line segment are at (-2, -1) and (2, 7). What is the slope-intercept equation for this line?
| y = 2x + 3 | |
| y = 2x - 2 | |
| y = 3x - 4 | |
| y = -3x - 4 |
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 3. 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, -1) and (2, 7) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(7.0) - (-1.0)}{(2) - (-2)} \) = \( \frac{8}{4} \)Plugging these values into the slope-intercept equation:
y = 2x + 3
A(n) __________ is to a parallelogram as a square is to a rectangle.
triangle |
|
quadrilateral |
|
trapezoid |
|
rhombus |
A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.