# ilorty

+2
29
2
+381
off-topic
ilorty  Aug 2, 2020
+4
32
3
+381
ilorty  Jul 29, 2020
+2
30
2
+381
ilorty  Jul 29, 2020
+3
79
8
+381
off-topic
ilorty  Jul 22, 2020
+2
46
0
+381
ilorty  Jul 20, 2020
+3
61
7
+381

### A bit stuck

ilorty  Jul 18, 2020
#1
+381
+1

This is not the formula itself, but part of the process in finding the formula. You will see if you click on the link.

The formula that says: AX=ac/(b+c)...

Plug in the coresponding values: 30(21)/(45+21)...

Can you solve that?

Aug 7, 2020
#2
+381
+1

Let TU and VW be chords of a circle, which intersect at S, as shown. If ST = 3, TU = 15, and VW = 3, then find SW.

Euclid's Proposition 36, book 3 states that ST*SU=SW*SV

Since we want to find SW to get SV, we can change SW to x.

We already know the other lengths:

ST=3

SU=18

SW=x

SV=x-3

So, 3(18)=x(x-3).

From here, we see that when expanded, this becomes 54=x^2-3x.

Solving the quadratic, we see that SW is 12, therefore SV is 9.

EDIT: Or, you could refer to the link in @above....(the steps and reasoning are slightly different, you can look there if you do not understand what I am talking about...)

:)

Aug 7, 2020