A circle has a circumference of 20. It has an arc of length 9/2. What is the central angle of the arc in degrees?

81 degrees

Step-by-step explanation:

The circumference is given by

C = 2*pi*r

20 = 2*pi*r

Divide each side by 2pi

20/2pi = 2*pi*r/2pi

10/pi =r

We know the arc length can be found by

s =r theta  where theta is in radians

9/2 = 10/pi *theta

Multiply each side by pi/10 to isolate theta

9/2 * pi/10 = pi/10 *10/pi *theta

9*pi/20 = theta

We need to convert to degrees

9*pi/20 * 180/pi

81 degrees

b

step-by-step explanation:

it have 5 sides and 5 identicle angle.the rest does not have the same property as b.

brainliest

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.