What is the shortest distance from the center to PQ?

[kittyhawk]

The radius of the circle show is 10 cm. PQ is 18 cm long. What is the shortest distance from the center to PQ?

 

[tkhunny]

If only we had your drawing before us. Sorry, you'll have to do better than that at the description.

 

[kittyhawk]

maybe this will help then:

 

[tkhunny]

Excellent!

1) Have you noticed that OP and OQ are radii - 10 cm?
2) This makes POQ an isosceles triangle.
3) OM is the central Altitude.
4) What do you know about the central altidude of an isosceles triangle?
5) This should lead you to the measure of MQ and MP, 9 cm. Do you see why?
6) Pythagoras will calculate the distance for you.

 

[kittyhawk]

I see that MP and MQ are 9cm and that OP and OQ are 10cm but when I try to calculate it my answer is huge. Which it shouldn't be. What formula should I use?

 

[kittyhawk]

wait. I think I got the answer. Is It 13.45?

 

[tkhunny]

\(\displaystyle \L\;\sqrt{10^{2} - 9^{2}}\)?

 

[kittyhawk]

ok now I get a different answer of 4.36 which seems to be right.

 

[tkhunny]

You're not filling me with confidence, but I guess you have it.