| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.34 |
| Score | 0% | 67% |
Which of the following statements about a triangle is not true?
exterior angle = sum of two adjacent interior angles |
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area = ½bh |
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sum of interior angles = 180° |
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perimeter = sum of side lengths |
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.
If AD = 29 and BD = 21, AB = ?
| 8 | |
| 17 | |
| 7 | |
| 19 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDWhat is 5a4 - 6a4?
| -1a4 | |
| -1 | |
| a48 | |
| 30a8 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
5a4 - 6a4 = -1a4
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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supplementary, vertical |
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acute, obtuse |
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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).
If side a = 8, side b = 1, what is the length of the hypotenuse of this right triangle?
| \( \sqrt{85} \) | |
| \( \sqrt{34} \) | |
| \( \sqrt{5} \) | |
| \( \sqrt{65} \) |
According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:
c2 = a2 + b2
c2 = 82 + 12
c2 = 64 + 1
c2 = 65
c = \( \sqrt{65} \)