Question

http://prntscr.com/b7p4nt

Answer 1

@jim_thompson5910

Answer 2

<b = 1/2 * <a
<c = 1/2 * 150°
A full circle has arc measure 360°

Can you find angle <b given the above facts?

Answer 3

Not quite
@owen3

Answer 4

From the picture we see that <a + 150 + 90 = 360, because a full circle makes 360 degrees.

Answer 5

You can find <a algebraically, right?

Answer 6

Yes haha

Answer 7

120

Answer 8

Now use the fact that
<b = 1/2 * <a

Answer 9

60

Answer 10

perfect :)

Answer 11

what about angle <c.
<c = 1/2 *150

Answer 12

<3

It's 1/2 of a?

Answer 13

Nope, I'm looking at <c.
we already found <a.

Answer 14

Hey

Answer 15

Do you know why both angles can be found using the same formula ?

Answer 16

Not exactly, no.

Answer 17

What is it one half one?

Answer 18

I used this website
http://www.mathwarehouse.com/geometry/circle/angle-tangent-and-chord.php

Answer 19

Nice

Answer 20

Do you know why the formula is the same as the inscribed angle theorem? That website didn't say why.

Answer 21

Hm, so it's half of 90+a?

No, I don't.

Answer 22

<c = 1/2 * 150

Answer 23

75

Answer 24

now you have all the angles .

Answer 25

Thank you sweetheart. Would you help me with some other questions?

Answer 26

I can't find a proof for this tangent chord theorem.