| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.10 |
| Score | 0% | 62% |
If the area of this square is 36, what is the length of one of the diagonals?
| 6\( \sqrt{2} \) | |
| 9\( \sqrt{2} \) | |
| 4\( \sqrt{2} \) | |
| 5\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{36} \) = 6
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 62 + 62
c2 = 72
c = \( \sqrt{72} \) = \( \sqrt{36 x 2} \) = \( \sqrt{36} \) \( \sqrt{2} \)
c = 6\( \sqrt{2} \)
The dimensions of this cylinder are height (h) = 9 and radius (r) = 9. What is the surface area?
| 4π | |
| 108π | |
| 324π | |
| 176π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(92) + 2π(9 x 9)
sa = 2π(81) + 2π(81)
sa = (2 x 81)π + (2 x 81)π
sa = 162π + 162π
sa = 324π
A quadrilateral is a shape with __________ sides.
2 |
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5 |
|
3 |
|
4 |
A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.
If angle a = 46° and angle b = 52° what is the length of angle d?
| 122° | |
| 120° | |
| 149° | |
| 134° |
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° - 46° - 52° = 82°
So, d° = 52° + 82° = 134°
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° - 46° = 134°
For this diagram, the Pythagorean theorem states that b2 = ?
c - a |
|
c2 - a2 |
|
c2 + a2 |
|
a2 - c2 |
The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c2) is equal to the sum of the two perpendicular sides squared (a2 + b2): c2 = a2 + b2 or, solved for c, \(c = \sqrt{a + b}\)