How do I make the legend of each curve appear in the graphic print area?

Question

grafico <- read.csv("Pasta1.csv", header = F, sep = ";")

library(ggplot2)

Experimental <- ggplot(grafico)+
  geom_line(size=1.2, aes(x=V1, y=V2))+
  scale_fill_manual(values = c("Experimental" = "green", "nulo" = "null"))

angulo30 <- Experimental+
  geom_line(size=1, col="blue", aes(x=V3, y=V4))

angulo36 <- plot30+
  geom_line(size=1, col="red", aes(x=V5, y=V6))

angulo42 <- plot36+
  geom_line(size=1, col="green", aes(x=V7, y=V8)) +
  labs(x="Displacement (mm)", y="Load (kN)")+
  theme_bw(base_size = 12)+
  theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank())+
  theme(axis.text.x = element_text(color = "black", size = 12), axis.text.y = element_text(color = "black", size = 12))

angulo42