Proving that an inscribed angle is half of a central angle that subtends the same arc.

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Pranav

5 years agoPosted 5 years ago. Direct link to Pranav's post “I need help in the proofs...”

I need help in the proofs for Case 3 in inscribed angles

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(16 votes)

toma.gevorkyan8

7 years agoPosted 7 years ago. Direct link to toma.gevorkyan8's post “Hi Sal, I have a question...”

Hi Sal, I have a question about the angle theorem proof and I am curious what happened if in all cases there was a radius and the angle defined would I be able to find the arch length by using the angle proof? Or I had to identify the type of angle that I am given to figure out my arch length? Thanks....

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(8 votes)

gavinjanz24

2 years agoPosted 2 years ago. Direct link to gavinjanz24's post “5 years later... I wonder...”

5 years later... I wonder if Sal is still working on it.

(11 votes)

kjohnson8937

2 years agoPosted 2 years ago. Direct link to kjohnson8937's post “can I use ψ as a variable...”

can I use ψ as a variable to measure any angle I want to?

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(4 votes)

kubleeka

2 years agoPosted 2 years ago. Direct link to kubleeka's post “Yes, and it doesn't have ...”

Yes, and it doesn't have to be an angle. You can assign any variable you like to any symbol you like. You can use Latin letters, Greek letters, Hebrew letters, random shapes, emoji, or anything else.

It's common practice to use the variables θ, φ, ψ for angle measures (I myself like to use η, since it's the letter before θ), but the rules aren't set in stone. Define whatever you like.

(6 votes)

Jason Showalter

4 years agoPosted 4 years ago. Direct link to Jason Showalter's post “What is the greatest meas...”

What is the greatest measure possible of an inscribed angle of a circle?

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(4 votes)

Pat Florence

4 years agoPosted 4 years ago. Direct link to Pat Florence's post “If the angle were 180, th...”

If the angle were 180, then it would be a straight angle and the sides would form a tangent line. Anything smaller would make one side of the angle pass through a second point on the circle. So the restriction on the inscribed angle would be:

0 < ψ < 180(5 votes)

Akira

4 years agoPosted 4 years ago. Direct link to Akira's post “What happens to the measu...”

What happens to the measure of the inscribed angle when its vertex is on the arc? Will it be covered in the future lecture?

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(5 votes)

Reynard Seow

3 years agoPosted 3 years ago. Direct link to Reynard Seow's post “If the vertex of the insc...”

If the vertex of the inscribed angle is on the arc, then it would be the reflex of the center angle that is 2 times of the inscribed angle. You can probably prove this by slicing the circle in half through the center of the circle and the vertex of the inscribed angle then use Thales' Theorem to reach case A again (kind of a modified version of case B actually).

(2 votes)

pandabuff2016

a year agoPosted a year ago. Direct link to pandabuff2016's post “is it possible to prove c...”

is it possible to prove case c without proving a & b first?

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(4 votes)

jonhlhn.surf

10 months agoPosted 10 months ago. Direct link to jonhlhn.surf's post “You do not need to prove ...”

You do not need to prove case B to prove case C, or vice-verse. But in proving case C (or proving case B), you need to prove case A first/along the way.

(3 votes)

taylor k.

4 years agoPosted 4 years ago. Direct link to taylor k.'s post “Do all questions have the...”

Do all questions have the lines colored? If not, how would you distinguish between the two?

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(3 votes)

victoriamathew12345

3 years agoPosted 3 years ago. Direct link to victoriamathew12345's post “Normally, to distinguish ...”

Normally, to distinguish between two lines, you would have letters instead.

E.g: f(x) vs g(x)(3 votes)

Konstantin Zaytsev

4 years agoPosted 4 years ago. Direct link to Konstantin Zaytsev's post “Why do you write m in fro...”

Why do you write m in front of the angle sign?

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(1 vote)

KC

4 years agoPosted 4 years ago. Direct link to KC's post “m=measure so it would jus...”

m=measure so it would just be the measure of the angle

(5 votes)

eperez3463

a year agoPosted a year ago. Direct link to eperez3463's post “how can i solve this”

how can i solve this

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(3 votes)

Trinity Kelly

5 years agoPosted 5 years ago. Direct link to Trinity Kelly's post “Ok so I have a small ques...”

Ok so I have a small question, I'm doing something called VLA and they gave me two different equations one to find the radius using the circumference, and the other to find the diameter also using the circumference, the equations were. Circumference/p = diameter, and the other was circumference/2p = radius, but i'm confused cause when I used the second one, it would give me a really big number while the first equation gave me a smaller number. Also sorry if this has nothing to do with what you were talking about Sal, I was waiting until I had enough energy to be able to ask my question.

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(1 vote)

kubleeka

5 years agoPosted 5 years ago. Direct link to kubleeka's post “When you compute C/2π, be...”

When you compute C/2π, be sure that you're dividing by π by putting the denominator in parentheses. If you just enter C/2*π, the calculator will follow order of operations, computing C/2, then multiplying the result by π.

(5 votes)