Question

If measures 135, what is the length of the radius of this circle? Round your answer to two decimal places.

Answer 1

I take it you did not understand the answer I posted to this question?

Answer 2

@phi i decided to skip it but i failed the test

Answer 3

oh. If you learn how to do these problems, you could pass.

what part is confusing you ?

Answer 4

i went back and read it just dont know how to solve it:(

Answer 5

use the formula...
(theta/360)2 pie r = 9

Answer 6

theta?

Answer 7

Here is the main idea:

a circle has a circumference (distance around it)
a circle is 360 degrees.

if you walk in a circle for 180º (for example) you only walked part way around the circle.
because 180 is ½ of 360, that means you walked half way around.

if you walked 120 degrees that is 120/360 = ⅓ of the way around the circle.

Answer 8

so you should be able to figure out: if I go 90º around a circle, what fraction of the circle is that ?

Answer 9

thetha means an angle...which in this case is 135 degree

Answer 10

1/4?

Answer 11

yes, exactly.

sudden posted the general formula. if we call the angle theta (90 in this case)
the fraction around the circle is theta/360. 90/360 in this example= ¼

Answer 12

*gudden

Answer 13

so think about that idea for a bit:

if you walk 30º out of 360º you walked 30/360 =3/36= 1/12 of the way (not very far)

Answer 14

if you walk 360 degrees you walked around the circle exactly once.

Answer 15

next, you probably should learn that the circumference (length around the circle) is
C= 2 pi r

where pi is 3.14159... (use 3.14 is a good choice)
and r is the radius

Answer 16

You really should practice on the earlier problems before tackling this one

If measures 135, what is the length of the radius of this circle?

Because this one is a "2 step" problem (not obvious)

but to figure it out, they tell you the angle is 135º
that means you should think: how far around the circle is that ? 135/360
which you could simplify to ⅜

next you notice the distance of the small part of the circle is 9 cm

you should think: ⅜ of the circle = 9 cm
or, better: ⅜ of circumference = 9 cm
we could write that as
⅜ * C = 9



step 2: formula for circumference is C= 2 pi r
if we replace C with 2 pi r in the other equation we get

⅜ * 2 * pi * r = 9
but you need to know a little algebra to "solve for r"

Answer 17

:D