Question

8. In ADEF, FG I DE and DH I EF. If DE = 18 cm,
EF = 20 cm and FG = 7 cm, find DH​

Answer 1

(1) ar(△DEF)=

2

1

×EF×12=300cm

2

⟹EF=

12

300×2

=50cm

(2) ar(△GEF)=

2

1

×EF×GK

=

2

1

×50×30=500cm

2

(3) ar(□DFGE)=ar△DEFar+△GEF

=300cm

2

+500cm

2

=800cm

2