Hello, I don't know how to overlay a histogram with a frequency polygon in the same graphic using ggplot2, it's for a work and I can only use ggplot2.
This is my code with the definition of the histogram and the frequency polygon

library(ggplot2)
library(readxl)

data <- countries_of_the_world

#Histogram
qplot(x = data$Deathrate,
geom = "histogram",
xlab = "Deathrate",
ylab = "Frequency",
main = "Histogram of Cumulative Relative Frequencies",
col = I("darkgreen"),
fill = I("green"))

#Frequency polygon
qplot(x = data$Deathrate,
geom = "freqpoly",
xlab = "Deathrate",
ylab = "Frequency",
main = "Histogram of Cumulative Relative Frequencies",
col = I("blue"))