| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.32 |
| Score | 0% | 66% |
What is the area of a circle with a diameter of 4?
| 7π | |
| 4π | |
| 36π | |
| 3π |
The formula for area is πr2. Radius is circle \( \frac{diameter}{2} \):
r = \( \frac{d}{2} \)
r = \( \frac{4}{2} \)
r = 2
a = πr2
a = π(22)
a = 4π
Which types of triangles will always have at least two sides of equal length?
equilateral and isosceles |
|
isosceles and right |
|
equilateral, isosceles and right |
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equilateral and right |
An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
supplementary, vertical |
|
acute, obtuse |
|
vertical, supplementary |
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obtuse, acute |
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 quadrilateral is a shape with __________ sides.
2 |
|
5 |
|
3 |
|
4 |
A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.
Solve for b:
b2 + 2b - 48 = 0
| 4 or 1 | |
| 8 or -9 | |
| 6 or -8 | |
| -1 or -3 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
b2 + 2b - 48 = 0
(b - 6)(b + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 6) or (b + 8) must equal zero:
If (b - 6) = 0, b must equal 6
If (b + 8) = 0, b must equal -8
So the solution is that b = 6 or -8