1

1

06

3

4 5

32+42=52

9+16=25

...

. ( )

C D

E

B

A

a b c

a

b

c

() () ,

() BC D ,ABC

90C222 CBACAB

ABC90C

2222 BCADCDAB

CB

A

a

bc

() ? () ?

() a=3,b=4 , c=?

. ( )