| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.03 |
| Score | 0% | 61% |
If side x = 8cm, side y = 14cm, and side z = 13cm what is the perimeter of this triangle?
| 35cm | |
| 29cm | |
| 28cm | |
| 23cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 8cm + 14cm + 13cm = 35cm
Solve for y:
y2 - 13y + 65 = 3y + 2
| 7 or 3 | |
| 7 or -1 | |
| 7 or 9 | |
| -1 or -2 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
y2 - 13y + 65 = 3y + 2
y2 - 13y + 65 - 2 = 3y
y2 - 13y - 3y + 63 = 0
y2 - 16y + 63 = 0
Next, factor the quadratic equation:
y2 - 16y + 63 = 0
(y - 7)(y - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y - 7) or (y - 9) must equal zero:
If (y - 7) = 0, y must equal 7
If (y - 9) = 0, y must equal 9
So the solution is that y = 7 or 9
Which of the following statements about a triangle is not true?
area = ½bh |
|
sum of interior angles = 180° |
|
exterior angle = sum of two adjacent interior angles |
|
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.
Solve for b:
-6b - 4 < -5 + b
| b < \(\frac{1}{7}\) | |
| b < \(\frac{3}{5}\) | |
| b < -\(\frac{3}{8}\) | |
| b < \(\frac{5}{6}\) |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the < sign and the answer on the other.
-6b - 4 < -5 + b
-6b < -5 + b + 4
-6b - b < -5 + 4
-7b < -1
b < \( \frac{-1}{-7} \)
b < \(\frac{1}{7}\)
If the base of this triangle is 9 and the height is 3, what is the area?
| 13\(\frac{1}{2}\) | |
| 84 | |
| 66 | |
| 48 |
The area of a triangle is equal to ½ base x height:
a = ½bh
a = ½ x 9 x 3 = \( \frac{27}{2} \) = 13\(\frac{1}{2}\)