Equations of Circles
What is the area of a circle with a radius of 14?
616
What is the formula to turn degrees into radians?
1° × π/180= 0.01745rad
A semicircle has how many degrees?
180
When the two circles are away from each other, then the number of common tangents will be?
4
What is the formula for the circumference of a circle?
2πr
A circle has a radius of 3 and a center located at the point (4,−5). What is the equation of the circle?
(x-4)2+(y+5)2=9
How many radians is an angle of 135o?
3π/4
A tangent to a circle is what to the radius of the point of tangency.
perpendicular
How many parallel tangents can a circle have?
2
What is the formula to find the area of a circle?
πr2
The equation of a circle is x2+(y−3)2=4. What are the coordinates of the center of the circle?
(0,3)
Convert 45o 30' into decimal degrees.
45.5o
The intercepted arc of an inscribed angle is how much to the measure of the angle.
double
If GA and GB are the tangents to the circle with center F and GA = 3x + 8, GB = 26, what is x?
6
What is the area of a circle that has a circumference of 8π?
16π
The graph of the quadratic equation: x2+y2+2x−6y+36=75 is a circle. What is the radius of the circle?
7
Convert 30o into radian measure of angles.
π/6 radians
An inscribed angle that intercepts a semicircle is what type of angle?
right angle
A circle of radius 7 is tangent to the lines of an angle 60o. is larger circle of radius, r is tangent to same lines as well as given circle, then value of r is:
21
If a circle has a diameter of 18 what is the circumference?
56.5
A circle has a radius of 4 and a center located at point (−5,2). What is the equation of the circle?
(x+5)2+(y−2)2=16
Express 4.7 radians into degree measure of angle.
269.2912o
An angle whose vertex is the center of a circle is what type of angle?
central angle
Find the equation of the tangent line to the curve y=ln(x2−8) at the point on the x-axis which is 3 units away from the origin.
y=6x-18
What is the area, of a circle whos diameter is 20?
314.2