Question

Help please! what is it i'm actually supposed to do??

The figure consists of a tangent and a secant to the circle.


A. 9.2

B. 7.7

C. 14.3

D. 85

Answer 1

There's a formula for this, but I don't remember it...

Answer 2

because x is a tangent to the circle, you can draw a line in to make a right angled triangle. then, use Pythagoras' theorem
(a^2=b^2+c^2)
to work out x
:)

Answer 3

only problem with that is that we are only given c, we still don't know b (if a = x)
Anyway, I've found this link that could help: http://www.mathwarehouse.com/geometry/circle/tangent-secant-side-length.php

Answer 4

I'm trying to load the page you found right now , but its not wanting to load :/

Answer 5

ok well this is what I've got:
c^2 = e * (a + e) <---- look familiar?
in this case c is x, e is 5, and a is 12. Plug them in and see what you get

Answer 6

okay , one moment.

Answer 7

Btw, this is what I wanted you to see

Answer 8

okay , so now it should look something like , x^2=5(12+5)?

Answer 9

x^2=31?

Answer 10

yeah.. looks right!

Answer 11

okay , so now how do i figure out x?

Answer 12

whoa, wait a sec.
x^2=5(12+5)
x^2 = 5* 17
x^2 = 85, right?

your answer will just be sqrt(85) I think

Answer 13

ohh i miscalculated , sorry :) the answer is 9.2

Answer 14

sounds right :]

Answer 15

thank you ! =)