| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.14 |
| Score | 0% | 63% |
The endpoints of this line segment are at (-2, -5) and (2, 7). What is the slope-intercept equation for this line?
| y = -2\(\frac{1}{2}\)x - 1 | |
| y = 1\(\frac{1}{2}\)x + 1 | |
| y = 3x + 1 | |
| y = -2\(\frac{1}{2}\)x + 0 |
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, -5) and (2, 7) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(7.0) - (-5.0)}{(2) - (-2)} \) = \( \frac{12}{4} \)Plugging these values into the slope-intercept equation:
y = 3x + 1
Which of the following is not true about both rectangles and squares?
the lengths of all sides are equal |
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all interior angles are right angles |
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the area is length x width |
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the perimeter is the sum of the lengths of all four sides |
A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s2).
What is the area of a circle with a radius of 4?
| 16π | |
| 9π | |
| 49π | |
| 4π |
The formula for area is πr2:
a = πr2
a = π(42)
a = 16π
If angle a = 39° and angle b = 27° what is the length of angle c?
| 89° | |
| 114° | |
| 100° | |
| 90° |
The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 39° - 27° = 114°
What is the circumference of a circle with a diameter of 12?
| 34π | |
| 8π | |
| 5π | |
| 12π |
The formula for circumference is circle diameter x π:
c = πd
c = 12π