Scribe Post for May 27, 2010

Hello 9-05. Sorry this is a late scribe ... I honestly forgot ... but this is for the day before the test, if you don't remember.

Anyways, in class we went over Question #21 on Page 403 in the textbook.





*The radius is 3cm because the diameter is 6cm (double the radius)*
Now we need to find out the purple measurement, and since it's a right angle, we could use the "Pythagorean Theorem".



Now that we know the radius of the circle that's sticking out of the ice surface (2.82cm) we could find the circumference.



The circumference of the circle where the ball touches the ice surface is 5.6(pi).

The rest of the class was work period, and since the test was the next day, Mr.B was asked a lot of questions.

I hope everyone did good on their tests, and good luck on finding out your marks (:
Have fun with what's left of the weekend!
Good luck to all the track people who won't be at school on Monday, and those who will be here, let's have fun again :D

HOMEWORK:
- stashits ---> journal, test signed, 2 problems of the week (including #3)

The next scribe is Marc. I told him on Friday, and reminded him again today. He's doing the test scribe ... but he said he'll do it "laterz" ... so just wait for it (; haha .

Scribe Post for May 25, 2010

Today in math class, we learned about tangents of a circle. First of all, what is a tangent (of a circle)?

A tangent is:

-a line that touches a circle at exactly one point

-the point where the line touches the circle is called the point of tangency

We also learned how to use the tangent chord relationship to find the unknown lengths, given in the diagrams. We used the Pythagorean theorem (only if there's a right triangle).

for example:

-find the length of AB (if BC (diameter) is 14 cm, and AC (hypotenuse) is 20 cm)

solution:

Then we learned how to determine angle measures in a circle with a tangent line.

-find the measure of angles A,B,C

To find A

180°=A+42°+90°

180°-132°=A

48°=A

To find C

Since C, is subtended by the same arc as A, A could be divided by two, then you'll get 24° for C.

To find B. (A+B=diameter(which is always 180°)

A+B=180°

48°+B=180°

B=180°-48°

B=132°

After those two examples, we had another example using the tangent chord relationship, once again.

-find the measure of line DE

solution:

Today's homework are:

-10.3 textbook

-read

-CYU #2

-Practice (odd)

-Apply : ALL

-Extend 19&21

-Workbook, and Extra Practice

-journal

TEST ON FRIDAY

For Tuesday, June 1

hand in inside stash-its

-problems of the week (#3, and another)

-journal

-last test signed