()
. ( , ()). , - . " " sqrt(), sqrt - , . "√".
.
DABC 13 ,14 , 15 . D 5 . D .
.
, .
. , , , , - . - , - .
. , :
p = (13 + 14 + 15) / 2 = 21
r = 4
, D , . :
52 = h2 + 42
h2 = 25 - 16
h2 = 9
h = 3
: 3 .
.
.
.
, . , . , .
60 .
, :
MAB = 30
ANK = 90
AKN = 180 - 90 -30 = 60 .
: 60
, 8, 5 . . 12. .
.
. , , . , AB = 10 , AO = 5 .
ON = 12 , AN NB
AN2 = AO2 + ON2
AN2 = 52 + 122
AN = √169
AN = 13
AO = OB = 5 (8 ), , ,
CB2 = CO2 + OB2
64 = CO2 + 25
CO2 = 39
CO = √39
, CN
CN2 = CO2 + NO2
CN2 = 39 + 144
CN = √183
|
|
: 13, 13, √183
, 8 6 . 10 . .
.
:
V = 1/3 Sh
:
S = ab/2 = 8 * 6 / 2 = 24
V = 1/3 * 24 *10 = 80 3.