## Wednesday, May 4, 2011

### Jomari's Post for May 4, 2011

Today we learned about perpendicular bisectors.
These are lines that bisect straight lines at 90°.
Here's how to make one:

We made these bisectors for several chords.

In a circle, we don't need to make crossed arcs on one side of the chord because of the center.
After wards, we answered a problem involving bisectors. It was similar to this:
A wheel is stuck in some water. The radius is 22cm and the water takes up 34cm lengthwise of the wheel. How deep is the wheel?
This is what we have to work with:

This question was difficult because of the way it was drawn, but he then realized we could do this:

WE COULD USE THE PYTHAGORAS THEOREM TO FIND B
a
²+b²=c²
17
²+b²=22²
289+b²=484
b²=484-289
b²=195
√ b²=√ 195²
b=13.96

22cm-13.96cm=8.04cm
THE WHEEL IS 8.04cm deep into the water