# A Different Look at Angles

## Instructions

#### Warning: Allow the Graphics and Java Applets to fully load before clicking anywhere

*If you accidentally interupt the transmission before it is finished by clicking
somewhere, you must press the "Refresh" button to start all over again from the beginning*

## Questions

- What is the measure of angle
*<AOC* when A=(15,20)?

- What is the slope of line
*AO*?

- Where do you need to put B so that the measure of angle
*<BOD* is the same as #1?

- What are the co-ordinates of point
*O* (test your answer by moving point
*A* there)?

- Where can you place
*A* so that *<AOC* is a 45° angle?

- What is the slope of line
*AO* now?

- Where above the line
*OD* can you place *B* so that *<BOD* is also a 45° angle?

- What is the slope of
*OB*?

- Notice that
*AO* and *OB* are perpendicular now. Place *A* at (40,20).
Where can you place *B* so that *AO* and *OB* are perpendicular?

- What is the slope of
*AO*?

- What is the slope of
*OB*?

- There is a relationship between the slopes of perpendicular lines. What is it?

- If you are confident you know what the relationship is, predict where
*A* should be
so that *AO* and *OB* are perpendicular when *B* is at (10,-10). Where should *A* be?

- What is the length of
*OB* (use the Pythagorean theorem or the disance formula)

- Where should
*B* be placed so that *OB* is 13 in length **and** *<BOD*=112.6°?

*Send me e-mail (frchris@mathorama.com)*