| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.14 |
| Score | 0% | 63% |
If angle a = 70° and angle b = 39° what is the length of angle d?
| 157° | |
| 146° | |
| 110° | |
| 151° |
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° - 70° - 39° = 71°
So, d° = 39° + 71° = 110°
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° - 70° = 110°
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
acute, obtuse |
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supplementary, vertical |
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vertical, supplementary |
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obtuse, acute |
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).
A trapezoid is a quadrilateral with one set of __________ sides.
equal length |
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right angle |
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equal angle |
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parallel |
A trapezoid is a quadrilateral with one set of parallel sides.
The dimensions of this cylinder are height (h) = 1 and radius (r) = 7. What is the surface area?
| 112π | |
| 132π | |
| 60π | |
| 198π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(72) + 2π(7 x 1)
sa = 2π(49) + 2π(7)
sa = (2 x 49)π + (2 x 7)π
sa = 98π + 14π
sa = 112π
The formula for the area of a circle is which of the following?
a = π d |
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a = π r |
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a = π r2 |
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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.