Segments, Length, and Distance: Practice

The bar names the segment as an object. The unmarked pair $AB$ denotes its numerical length in a chosen unit.

Subtract the smaller coordinate from the larger.

$CD=8-(-3)=11$

The distance includes the three units from $-3$ to zero and eight more to $8$.

Use the difference of the coordinates, not the sum of their distances from zero.

$EF=|-9-(-17)|=8$

Both coordinate readings are the same, so their difference is zero. The distance from a location to itself is $0$.

Betweenness makes the two given lengths adjacent parts of the whole segment.

$AC=11+14=25\text{ cm}$

The whole is $LP$, so subtract the known part.

$NP=41-16=25\text{ mm}$

Congruent segments have equal lengths. Direction and position do not change that definition.

A midpoint divides a segment into equal halves.

$RM=32\div2=16$

Average the endpoint coordinates.

$\frac{-10+6}{2}=-2$

The distances from $-2$ to the endpoints are both $8$ units.

A segment bisector passes through the midpoint. Perpendicularity is an additional condition and is not required for bisection.

Subtract the endpoint readings.

$10-3=7\text{ cm}$

The endpoint does not have to start at zero.

Compare the lengths in the same unit. Each centimeter contains ten millimeters.

$2.7\times10=27\text{ mm}$

Thus $AB$ and $CD$ are equal lengths, so the segments are congruent.

Different unit labels do not change that length.

Also, $CD=2.7$ centimeters and $AB=27$ millimeters, so the other numerical claims are false.