9
AB=√(AC²+BC²)=√324+100=√424=2√106
AO=BO=√106
ON_|_AC,ON=1/2*BC=5
OK_|_BC,OK=1/2*AC=9
MN=√OM²+ON²=√144+81=√225=15
MK=√OK²+OM²=√144+25=√169=13
2 3 5 8 12 17 23 30 38 47
<span>2+1=3 </span>
<span>3+2=5 </span>
<span>5+3=8 </span>
<span>8+4=12 </span>
<span>12+5=17 </span>
<span>17+6=23 </span>
<span>23+7=30 </span>
<span>30+8=38 </span>
<span>38+9=47</span>