Given:
In the given circle O, BC is diameter, OA is radius, DC is a chord parallel to chord BA and 
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To find:
The 
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Solution:
If a transversal line intersect two parallel lines, then the alternate interior angles are congruent.
We have, DC is parallel to BA and BC is the transversal line.
[Alternate interior angles]
In triangle AOB, OA and OB are radii of the circle O. It means OA=OB and triangle AOB is an isosceles triangle.
We know that base angles of an isosceles triangle are congruent.
[Base angles of an isosceles triangle]
In triangle AOB,
Therefore, the measure of angle AOB is 120 degrees.
Answer:
Step-by-step explanation:
We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean
For the null hypothesis,
µ = 17
For the alternative hypothesis,
µ < 17
This is a left tailed test.
Since the population standard deviation is not given, the distribution is a student's t.
Since n = 80,
Degrees of freedom, df = n - 1 = 80 - 1 = 79
t = (x - µ)/(s/√n)
Where
x = sample mean = 15.6
µ = population mean = 17
s = samples standard deviation = 4.5
t = (15.6 - 17)/(4.5/√80) = - 2.78
We would determine the p value using the t test calculator. It becomes
p = 0.0034
Since alpha, 0.05 > than the p value, 0.0043, then we would reject the null hypothesis.
The data supports the professor’s claim. The average number of hours per week spent studying for students at her college is less than 17 hours per week.
Answer:
D. 25°
Step-by-step explanation:
The triangle is an isosceles triangle with exactly two congruent angles.
Since the two 45-deg angles are congruent, their opposite sides are also congruent. That makes y = 5.
This triangle is a 45-45-90 triangle. In a 45-45-90 triangle, the legs are congruent and the hypotenuse is sqrt(2) times the length of the legs.
The hypotenuse has length x, so x = 5 * sqrt(2) = 5sqrt(2)
Answer: B. x = 5sqrt(2), y = 5
