Question

The circle in the figure above has center A. Which of the following measures for the figure would be sufficient by itself to determine the radius of the circle?

I. The length of arc DEC

II. The perimeter of ADC

III. The length of chord DC

Answer 1

ehh I and three seem promising

Answer 2

any suggestions?

Answer 3

well do you know the formula for arc length?

Answer 4

ehhh

Answer 5

not exactly...

Answer 6

arc length = (angle to form the arc)* radius

Answer 7

k...

Answer 8

we have the angle... so what else would we need to solve for r?

Answer 9

give me a moment

Answer 10

k

Answer 11

I'm back

Answer 12

arc length = (angle to form the arc)* radius

we have the angle... so what else would we need to solve for r?

Answer 13

The length of the chord?

Answer 14

look at the formula i posted

Answer 15

arc length = (angle to form the arc)* radius

Answer 16

we could use it to solve for radius

Answer 17

we need the length of the radius?

Answer 18

sure so if:
arc length = (angle to form the arc)* radius

then couldnt we say that

arclength/(angle to form arc) = radius

Answer 19

ohhh

Answer 20

so we need the I and III.

Answer 21

wait

Answer 22

we already got the angle to begin with

Answer 23

so we only need the arc

Answer 24

perfecto

Answer 25

so we only need I.

Answer 26

yes sir

Answer 27

can we do a few more?

Answer 28

one more

Answer 29

k