INTERMEDIATE LEVEL 7. Devi folded a sheet of paper into an envelope, as
shown in the figure. In the figure, ZAED = ZADB
= ZBCD = 90°. To seal the envelope, she has to
apply glue along AD and DB. Given that AE = ED
= 8 cm and DC = BC = 14 cm, find the total length
of the sides along which the glue has to be applied
to seal the envelope.
B
A
14 cm
8 cm +
E
D
С