Measuring Line Segments

[DamienDunce]

These questions were on my assignment and I completely didn't understand. I'm doing online school due to the pandemic, and online kids are real overlooked here, so nothing was explained to me at all. I would really appreciate some help as math is my worst subject. (Sorry if I mess up, it's my first time posting.)

 

[Otis]

Hi Damien. In each diagram, the vertical tick marks indicate the two segments have the same length. For example, in exercises #5 and #6, the tick marks tell us that segment AM has the same length as segment MB. In each exercise, they've also given a length for one segment (eg: in exercise #5, segment AM is 15 units long). Is that enough explanation, for you to try? If you're not sure, please explain what's confusing.

In exercises #7 and #8, we have the same situation, except the given measurements are symbolic instead of numeric (i.e., they are expressions containing symbol x). We can write an equation to solve for x because we know the two halves are equal in length. After we find the value of x, we can evaluate the lengths.

SM = MT

What do you think the equation is for exercise #7?

?

 

[Steven G]

Otis, so you are saying that the 15 above the left tick mark is not saying that the value at that tick mark is 15 but rather that the length from A to M is 15?

I am interpreting this tick marks as the 1/4 and 3/4 points from A to B.

For the student's sake I hope that you are wrong. Why unearth would they put a number directly above the tick mark if that is NOT the value at the tick mark? I suspect that you are correct as that is the only way to get a solution.

I will need a few moments to recover from this post.

 

[Dr.Peterson]

Otis, so you are saying that the 15 above the left tick mark is not saying that the value at that tick mark is 15 but rather that the length from A to M is 15?

I am interpreting this tick marks as the 1/4 and 3/4 points from A to B.

For the student's sake I hope that you are wrong. Why unearth would they put a number directly above the tick mark if that is NOT the value at the tick mark? I suspect that you are correct as that is the only way to get a solution.

I will need a few moments to recover from this post.

I think you're reading this as a number line. But this is about geometry, and about congruent segments, so it makes sense that any labels are lengths, not coordinates. Also, if those numbers were coordinates, the problems would be impossible!

I suspect that if we saw the context (such as the rest of the page) there would be no ambiguity.

 

[Otis]

Otis, so you are saying that the 15 above the left tick mark [says] the length from A to M is 15? …

Yes.

… Why unearth (sic) would they put a number directly above the tick mark if that is NOT the value at the tick mark? …

Maybe they didn't think twice about it because they normally label points on a number line by writing the values directly below the tick marks, instead. (I can only speculate, as to why they did it the way they did.)

Fix yourself a lovely beverage.

 

[Steven G]

Yes.


Maybe they didn't think twice about it because they normally label points on a number line by writing the values directly below the tick marks, instead. (I can only speculate, as to why they did it.)

Fix yourself a lovely beverage.

I already did! JD (Jack Daniels) and coke.