On a 30-question test, Janice answered four-fifths of the questions correctly. Which of the following is the number of questions
1 answer:
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Answer:
You use the facts about a 30, 60, 90 triangle.
Step-by-step explanation:
The angles in a triangle add up to 180.
90+30+x=180
120+x=180
x=60
This is a 30-60-90 right triangle.
The side opposite the 30 degree angle is a.
The side opposite the 90 degree angle (hypotenuse) is 2a.
The side opposite the 60 degree angle is a
We know the side opposite the 90 degree angle.
2a = 12
Divide by 2.
a=6
a is the side opposite the 30 degree angle (y)
Because we know a, we can find a.
6
The square roots cancel, leaving 3.
6 times 3 is 18.
Therefore, the side opposite the 60 degree angle (x) is 18.
