Zjistěte velikosti stran trojúhelníku ABC, je-li A =[3; 2]; B= -1;-1 ; C = 11;-6 .
Odpovědi
Diskuze
B[-1,-1]
vektor AB:
AB=B-A=(1-(-3),(-1)-2)=(4,-3)
velikost vektoru:
|AB|=( 4*4+(-3)*(-3) )^(1/2)
|AB|=( 16+9 )^(1/2) = 5
|AB|= 5
=======
A[3,2]
C[11,-6]
vektor AC:
AC=C-A=(11-3,(-6)-2)=(8,-8)
velikost vektoru:
|AC|=( 8*8+(-8)*(-8) )^(1/2)
|AC|=( 64+64 )^(1/2) = 8*(2)^(1/2)
|AC|= 8*(2)^(1/2)
|AC|= 11,313708498984760390413509793678
=======
B[-1,-1]
C[11,-6]
vektor AC:
BC=C-B=(11-(-1),(-6)-(-1))=(12,-5)
velikost vektoru:
|BC|=( 12*12+(-5)*(-5) )^(1/2)
|AC|=( 144+25 )^(1/2) = ( 169 )^(1/2)
|AC|= 13
=======
AC=C-A=(11-3,(-6)-2)=(8,-8)
|AC|=128^1/2 =cca 11,31