Geometry With R

Area of a circle

## Warning: package 'plotrix' was built under R version 3.4.3

In my math class, we are studying how to calculate the area, circumference and diameter of a circle.

circlearea_r <- function(pi, radius) {
  
  area_circle <- pi*radius^2
}

test_circle <- circlearea_r(22/7, 5)

test_circle

## [1] 78.57143

circlearea_d <- function(pi, diameter) {
  
  area_circle <- (pi*diameter^2)/4
}

test_circled <- circlearea_d(22/7, 12)  

test_circled

## [1] 113.1429

circle_area_c <- function(pi, circum) {
  
  area_circle <- (circum^2)/(4*pi)
}
  
test_circlec <- circle_area_c(22/7, 16)
  
test_circlec

## [1] 20.36364

ggplot() + geom_circle(aes(x0 = 0, y0 = 0, r = 5, fill = 5))

symbols (0, 0, circles=1,fg="red")

 # plot(BOD)
 # require(plotrix)
 # draw.circle(4,14,2,border="blue",col="tan2")