Answer: a. 90°
Step-by-step explanation:
We know that the in a circle, the measure of an inscribed angle is half the measure of the central angle with the same intercepted arc.
In the problem∠XYZ is the inscribed angle
∠XYZ=
⇒ ∠XYZ=
Since XZ is a diameter of the circle which is a line segment, thus ∠XZ=180°
∴ ∠XYZ=
∴ ∠XYZ=
Therefore, a. 90° is the measure of ∠XYZ.
Answer:
Her usual driving speed is 38 miles per hour.
Step-by-step explanation:
We know that:
In which s is the speed, in miles per hour, d is the distance, in miles, and t is the time, in hours.
We have that:
At speed s, she takes two hours to drive. So
However, on one particular trip, after 40% of the drive, she had to reduce her speed by 30 miles per hour, driving at this slower speed for the rest of the trip. This particular trip took her 228 minutes.
228 minutes is 3.8 hours. So
So
Her usual driving speed is 38 miles per hour.