| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
Which of the following statements about a triangle is not true?
area = ½bh |
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exterior angle = sum of two adjacent interior angles |
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perimeter = sum of side lengths |
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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.
If angle a = 36° and angle b = 44° what is the length of angle d?
| 140° | |
| 127° | |
| 144° | |
| 114° |
An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:
d° = b° + c°
To find angle c, remember that the sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 36° - 44° = 100°
So, d° = 44° + 100° = 144°
A shortcut to get this answer is to remember that angles around a line add up to 180°:
a° + d° = 180°
d° = 180° - a°
d° = 180° - 36° = 144°
If AD = 29 and BD = 25, AB = ?
| 10 | |
| 4 | |
| 5 | |
| 11 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDIf a = c = 6, b = d = 7, what is the area of this rectangle?
| 40 | |
| 63 | |
| 27 | |
| 42 |
The area of a rectangle is equal to its length x width:
a = l x w
a = a x b
a = 6 x 7
a = 42
If the base of this triangle is 8 and the height is 8, what is the area?
| 25 | |
| 24 | |
| 32 | |
| 36 |
The area of a triangle is equal to ½ base x height:
a = ½bh
a = ½ x 8 x 8 = \( \frac{64}{2} \) = 32