Circle A has a radius of 4 and arc BD has length of 6.5.

Circle C is a different circle with radius 6 and arc EF. Angle ECF is congruent to angle BAD.
What is the length of arc EF?
Enter your answer as a number, like this: 42.25

I tried to use the arc length equation and equal them to each other, but I kept getting x=0..... I do not know what to do please help me.

It's just a direct proportion ...

arc EF/6.5 = 6/4 = 3/2
2(arc EF) = 3(6.5)
arc EF = ...

or, you could do your arclength thing: arc = rØ,
for smaller circle:
4Ø = 6.5
Ø = 6.5/4

for larger circle: let arclength EF = x
6Ø = x
Ø = x/6

then
x/6 = 6.5/4
x = 6(6.5)/4 = same as above

To find the length of arc EF, we can use the fact that angles ECF and BAD are congruent.

Since the radius of circle A is 4 and arc BD has a length of 6.5, we can calculate the measure of angle BAD using arc length formula:

arc length = radius * angle in radians

6.5 = 4 * angle BAD

Solving for angle BAD:

angle BAD = 6.5 / 4

Now that we know the measure of angle BAD, we can find the length of arc EF using the formula:

arc length = radius * angle in radians

arc EF = radius of circle C * angle ECF

Given that the radius of circle C is 6 and angle ECF is congruent to angle BAD, we substitute the values:

arc EF = 6 * (6.5 / 4)

Simplifying:

arc EF = 39 / 4

Therefore, the length of arc EF is 9.75 units.

To solve this problem, we can use the concept of "proportional arcs" in circles. If two angles in different circles are congruent, then the lengths of their corresponding arcs in each circle are also congruent.

First, let's find the measure of angle BAD in terms of radians.

Given that circle A has a radius of 4 and arc BD has a length of 6.5, we can use the formula for arc length:

arc length = radius * angle (in radians)

So, 6.5 = 4 * angle (in radians)

Dividing both sides by 4, we get:

angle (in radians) = 6.5/4 = 1.625

Now, since angle ECF is congruent to angle BAD, we can use the same measure: 1.625 radians.

Next, let's find the length of arc EF in circle C.

Using the formula for arc length, we have:

arc length = radius * angle (in radians)

For circle C, the radius is 6 and the angle is 1.625 radians. Substituting these values into the formula, we get:

arc length EF = 6 * 1.625 = 9.75

Therefore, the length of arc EF is 9.75 units.