| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
The formula for the area of a circle is which of the following?
a = π r |
|
a = π d |
|
a = π r2 |
|
a = π d2 |
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.
Solve for c:
c2 - 9 = 0
| 3 or -3 | |
| -2 or -2 | |
| -6 or -7 | |
| 4 or 3 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
c2 - 9 = 0
(c - 3)(c + 3) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c - 3) or (c + 3) must equal zero:
If (c - 3) = 0, c must equal 3
If (c + 3) = 0, c must equal -3
So the solution is that c = 3 or -3
If a = c = 5, b = d = 6, and the blue angle = 51°, what is the area of this parallelogram?
| 35 | |
| 56 | |
| 30 | |
| 54 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 5 x 6
a = 30
If a = 6, b = 6, c = 2, and d = 2, what is the perimeter of this quadrilateral?
| 15 | |
| 24 | |
| 16 | |
| 21 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 6 + 6 + 2 + 2
p = 16
The dimensions of this cube are height (h) = 7, length (l) = 9, and width (w) = 6. What is the surface area?
| 48 | |
| 318 | |
| 162 | |
| 262 |
The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):
sa = 2lw + 2wh + 2lh
sa = (2 x 9 x 6) + (2 x 6 x 7) + (2 x 9 x 7)
sa = (108) + (84) + (126)
sa = 318