Given AB=12cm,AC=13cm,CE=10cmandDE=6cm
ABC is a right triangle.
AC2=AB2+BC2[Pythagoras theorem]
132=122+BC2
BC2=132−122
BC2=169−144
BC2=25
Taking square root on both sides,
BC=5cm
CDE is a right triangle.
CE2=CD2+DE2[Pythagoras theorem]
102=CD2+62
100=CD2+36
CD2=100−36
CD2=64
Taking square root on both sides,
CD=8cm
BD=BC+CD
BD=5+8
BD=13cm
Hence the length of BD is 13cm.