2SQOHDA R  = Π=Π =0360123 2 2 2 A23214=> S = ( )AA − − Π = − Π16482

2 . - DAP AN MON TOAN TS VAO LOP 10 NAM 2010-2011
Lớp 10 Toán DAP AN MON TOAN TS VAO LOP 10 NAM 2010-2011

2 .

=>

2

a

AOH

.

2

S

qOHDA

R  = Π

=

Π =

0

360

12

3

2 2 2

a

2

3

21

4

=> S = ( )

a

a − − Π = − Π

16

48

2