The next step is to drawthe secondsegment.Use a pencilto createthe segmentaccordingto the specifi-
cationsin the problem.You knowthat the segmentneedsto be congruentto the first, so it will be 4 units
long.The problemalso statesthat it travelsstraightup from the point(-1,1).Drawin the pointat (-1,1)and
makea line segment4 unitslong that travelsstraightup.
Now that you havedrawnin the new segment,use the grid to identifythe new endpoint.It has an -coor-dinateof -1 and a -coordinateof 5. So, its coordinatesare (-1,5).
SegmentMidpoints
Now that you understandcongruentsegments,thereare a numberof new termsand typesof figuresyou
can explore.Asegmentmidpointis a pointon a line segmentthat dividesthe segmentinto two congruent
segments.So, eachsegmentbetweenthe midpointand an endpointwill havethe samelength.In the diagram
below, point is the midpointof segment since is congruentto.
Thereis evena specialpostulatededicatedto midpoints.
SegmentMidpointPostulate:Any line segmentwill haveexactlyone midpoint—nomore,and no less.
Example 2
Nandiand Arshadmeasureand find that their housesare 10 milesapart.If they agreeto meetat the midpoint
betweentheir two houses,how far will eachof themtravel?
The easiestway to find the distanceto the midpointof the imaginedsegmentconnectingtheir housesis to
dividethe lengthby 2.