| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.46 |
| Score | 0% | 69% |
If a = c = 7, b = d = 8, and the blue angle = 55°, what is the area of this parallelogram?
| 12 | |
| 45 | |
| 7 | |
| 56 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 7 x 8
a = 56
The formula for the area of a circle is which of the following?
a = π d2 |
|
a = π r2 |
|
a = π d |
|
a = π r |
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 side x = 12cm, side y = 14cm, and side z = 13cm what is the perimeter of this triangle?
| 37cm | |
| 35cm | |
| 33cm | |
| 39cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 12cm + 14cm + 13cm = 39cm
Simplify (y + 9)(y + 7)
| y2 - 2y - 63 | |
| y2 - 16y + 63 | |
| y2 + 16y + 63 | |
| y2 + 2y - 63 |
To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:
(y + 9)(y + 7)
(y x y) + (y x 7) + (9 x y) + (9 x 7)
y2 + 7y + 9y + 63
y2 + 16y + 63
Factor y2 - y - 42
| (y - 7)(y + 6) | |
| (y + 7)(y - 6) | |
| (y - 7)(y - 6) | |
| (y + 7)(y + 6) |
To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -42 as well and sum (Inside, Outside) to equal -1. For this problem, those two numbers are -7 and 6. Then, plug these into a set of binomials using the square root of the First variable (y2):
y2 - y - 42
y2 + (-7 + 6)y + (-7 x 6)
(y - 7)(y + 6)