| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.89 |
| Score | 0% | 58% |
Which of the following is not true about both rectangles and squares?
the area is length x width |
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all interior angles are right angles |
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the lengths of all sides are equal |
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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).
The dimensions of this trapezoid are a = 6, b = 3, c = 9, d = 8, and h = 5. What is the area?
| 10\(\frac{1}{2}\) | |
| 16 | |
| 27\(\frac{1}{2}\) | |
| 22 |
The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:
a = ½(b + d)(h)
a = ½(3 + 8)(5)
a = ½(11)(5)
a = ½(55) = \( \frac{55}{2} \)
a = 27\(\frac{1}{2}\)
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
obtuse, acute |
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acute, obtuse |
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supplementary, vertical |
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vertical, supplementary |
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).
Which of the following statements about a triangle is not true?
exterior angle = sum of two adjacent interior angles |
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perimeter = sum of side lengths |
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area = ½bh |
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sum of interior angles = 180° |
A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.
Solve for c:
c2 + 11c + 28 = 0
| 9 or 2 | |
| -4 or -7 | |
| 7 or -1 | |
| 5 or -7 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
c2 + 11c + 28 = 0
(c + 4)(c + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 4) or (c + 7) must equal zero:
If (c + 4) = 0, c must equal -4
If (c + 7) = 0, c must equal -7
So the solution is that c = -4 or -7