Namethe threepolygonsbelowby their numberof sides.
A. This shapehas sevensides,so it is a heptagon.
B. This shapehas five sides,so it is a pentagon.
C. This shapehas ten sides,so it is a decagon.
Usingthe DistanceFormulaon Polygons
You can use the distanceformulato find the lengthsof sidesof polygonsif they are on a coordinategrid.
Rememberto carefullyassignthe valuesto the variablesto ensureaccuracy. Recallfrom algebrathat you
can find the distancebetweenpoints and usingthe followingformula.
Example 5
A quadrilateralhas beendrawnon the coordinategrid below.
Whatis the lengthof segment?
Use the distanceformulato solvethis problem.The endpointsof are (-3,9)and (4,1).Substitute-3
for , 9 for , 4 for , and 1 for. Thenwe have: