Răspuns:
1.
AC^2 + AB^2 = BC^2 (t.Pitagora)
DE^2 = EF^2 - DF^2 (t.Pitagora)
2.
BC^2 = 12^2 + 9^2
BC^2 = 144 + 81
BC^2 = 225 =>BC=15
EF^2 = DF^2 + DE^2
EF^2 = 256 + 144
EF^2 = 400 =>EF=20
HI^2 = GI^2 - HG^2
HI^2 = 25^2 - 7^2 = (25-7)(25+7)
HI^2 = 18•32
HI^2 = 2 • 3^2 • 2^5 = 2^6 • 3^2
HI = 2^3 • 3
HI = 24
RQ^2 = RP^2 - PQ^2
RQ^2 = 250 - 169
RQ^2 = 81 =>RQ=9
