Answer:
19. C
20. D
21. B
22. A
Step-by-step explanation:
If an angle is subtended from an arc and it goes to the opposite end of the circle, the angle is HALF of the measure of the arc. If it goes to the center, it is SAME measure as arc.
19.
Arc BC is DOUBLE of Angle BAC, so
78 * 2 = 156
Answer is C
20.
Arc BEC is DOUBLE of Angle BAC, so
114 * 2 = 228
Answer is D
21.
Angle ABC is HALF of Arc AC, so
Angle ABC = 110/2 = 55
Answer is B
22.
Angle ABC is HALF of Arc AC, so
Angle ABC = 218/2 = 109
Answer is A
The standard equation of a circle is
(x-h)^2 + (y-k)^2 = r^2
where the center is at point (h,k)
From the statement of the problem, it is already established that h = 2 and k = -5. What we have to determine is the value of r. This could be calculated by calculating the distance between the center and point (-2,10). The formula would be
r = square root [(x1-x2)^2 + (y1-y2)^2)]
r = square root [(2--2)^2 + (-5-10)^2)]
r = square root (241)
r^2 = 241
Thus, the equation of the circle is
To find x:
use the formula: tan° = opposite/adjacent
tan 61° = x/10
answer: 18.0
other length:
use the formula: cos° = adjacent/hypo
cos 61° = 10/y
answer: 20.6