About this video
This video shows how to name an angle using three points, with the vertex letter in the middle. Angle CPA can also be called angle APC, while names like angle P, angle PAC or angle FPA do not describe the same angle.
You'll be able to
- name an angle using three letters with the vertex in the middle.
- explain why a one-letter name like angle P can be unclear.
Key words
- angle
- The opening between two rays or segments that meet at a point.
- vertex
- The point where the two sides of an angle meet; its letter goes in the middle of the name.
Transcript
What is another name for angle CPA? So we have C, we have P, and we have A. So angle CPA is going to be this angle right over here. So what's another name for it? Well, I could start off with A, and I could call it angle APC. So this is the same thing as angle APC.
Now is that any one of my choices? Yeah, that's this choice right over here. If someone said angle P, that wouldn't give you a lot of information. That kind of says, well, that's only giving me one point. I don't know, maybe it's referring to that angle, that angle, that angle, that angle.
So that's really not giving me enough information to specify this angle right over here. Angle PAC would be an angle formed if you actually had a line here, if you had a line between AC. Angle PAC would be this angle right over here, which is clearly a different angle.
Angle FPA would be this angle right over here, which is also clearly a different angle. So the only choice that makes sense is angle APC.
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