tolong bantu no 3 dongg..

BC = √AC2 - AB2
BC = √25 - 9 = √16 = 4 cm.

luas segitiga = 2 (axt÷2) = 2(4x3÷2) = 2 x 6=12 cm2
luas persegi pnjg = (p1xl1)+(p2xl2)+(p3xl3)
= (7x5) +(7x4)+(7x3) = 35+28+21= 84cm2
luas permukaan = 84+12=96cm2