.
A 1 .
A , A √5 .
.
. , , √5 .
, , , :
2 + 1 = 5
2 = 4
x = 2
: 2 .
. ( ). , - .
., , , .
.
, . , , , .
:
" , . "
.
.
4 , 6 .
.
.
.
, OKC .
KC2 + OK2 = OC2
KC2 = OC2 - OK2
KC2 = 36 - 16
KC = √20 = 2√5
KC * 2 = 4√5
: 4√5
.
O - ABC OM ABC.
OM, BC=6, MC=4.
.
, .
- . ABC - , - , OC .
R = a √3 / 3
OC = BC√3 / 3
OC = 6√3 / 3 = 2√3
OM2 + OC2 = MC2
OM2 = MC2 - OC2
OM2 = 16 - 12
OM = 2
: 2