Find the measure of angle BAC
Any numbers?
The number in the center is 68 @Directrix
and the possible answers are A. 57 degrees B. 114 degrees C. 66 degrees D. 123 degrees
Do you know how many degrees are in a circle?
360
correct. now you see that the line AC is bisecting that circle in half right? How many degrees does that leave you if you cut the circle in half?
Here is the marked up diagram. I will wait until heycoa finishes working with you. @blossombuttercupandbubbles1234
@Directrix I think I am finished working with heycoa. I saw your diagram and i was wrong the numbder in the middle is 66
whoops, I could not make out the first picture, I was not doing the problem correctly!
Maybe this is the correct diagram.
Yep that works! 66 + 114 = 180
@Directrix
How do you get the measure of an inscribed angle of a circle? What does that theorem state? @blossombuttercupandbubbles1234 @heycoa
the measure of an inscribed angle is half the measure of its intercepted arc
@Directrix
Yes, and the measure of the intercepted arc is what? @blossombuttercupandbubbles1234
Look at the diagram.
@Directrix 66?
Look on the diagram to see where I extended the "jaws" of the angle at B and C. The angle "bites off" the blue arc. It has measure 114. So, take half of 114 and you get ? @blossombuttercupandbubbles1234
@Directrix I get 57. I would add 57 + 66 and get the measure of angle BAC. Is this right?
114 divided by 2 = 57. I get 57 for the measure of the angle BAC. Look at the diagram and see if I marked the letters in the right place. It was hard to see on the original diagram you posted.
@Directrix yeah I know it was really fuzzy, but look on the bright side you will get best answer. My next question is this: Given that angle DAB and angle DCB are right angles and m ACD = 310, what is the measure of angle ADB A. 51 degrees B. 65 degrees C. 33 degrees D. 115 degrees
See if you agree with the diagram. Is the measure of arc AB = 130?
@Directrix Yes if AD is 50
Then AB is 130
What is the measure of ADB though,
Arc DAB is a semicircle. That right angle is inscribed so it cuts off a 180 degree arc. Segment BD is the diameter of the circle.
Angle ADB is an inscribed angle. How do you get the measure of an inscribed angle of a circle. We just did that on the previous problem.
Yes, half of 130 = 65 or is it half of 65 @Directrix
Half of the arc it bites off. So --> Yes, half of 130 = 65
So then is the measure of the angle ADB 65?
@Directrix do you think that's right?
Yes, I do. @blossombuttercupandbubbles1234
@Directrix Great Thanks! I have one more question and that will be my last for the night! If m BY= 38, what is m YAC? A. 128 degreed B. 109 degrees C. 71 degrees D. 218 degrees
You draw the diagram and mark it up this time around.
|dw:1359360460655:dw|@Directrix
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