Two poles of height 9 m and 14 m stand on a plane ground. If the distance between their feet is 12 m, find the distance between their tops.
We have,
AC=14m, DC=12m, ED=BC=9m
Draw EB ⊥ AC
∴ AB=AC-BC
AB= 14-9=5m
EB=DC=12m
In 
ABE
AE2=AB2+BE2
AE2=52+122
AE2=25+144
AE2=169
AE=
AE=13m
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