Investigation 3:

**1.(a)**Use what you know about chords to find the centre of the circle. Erase all construction lines once you're done.

This is how you do question

**1.(a)**(If you do have any questions, this question is explained in the previous scribe):

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**(b)**Construct diameter AB.

Heres what you do:

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**(c)**Choose 4 different points on the circumference of the circle. Do not space them out evenly. Label these points C, D, E and F.

This questions is self-explanatory:

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**(d)**Construct chords AC and BC.

**(e)**Measure the angle formed at C

Draw lines from A to C and from B to C and measure the angle C:

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**(f)**Repeat steps

**(c)**and

**(d)**for the points labeled D, E and F.

It's pretty straight forward:

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**(g)**What do you notice about all these angles? Can you articulate a general rule for what you have found? Your sentence should begin:

"

**If**an inscribed angle is subtended by a diameter

**then**...."

**If**an inscribed angle is subtended by a diameter

**then**.... the inscribed angle is always 90°.

So that was Investigation 3. We started Investigation 4 but did not get a chance to go over it in class. THE SCRIBE FOR THE WEEKEND IS ..

**SANDY !**