Correct function definition syntax

Exercise Type: Correction

Instructions

Correct the following, syntactically wrong function definitions:

A.

# function to calculate the area area of a circle
CircleArea <- function{r} (r^2 * 3.14)

B.

# function to calculate area of a rectangle
RectArea <- function(a,b} a * b}

C.

CelsiusToFahrenheit <- function(celsius{
	# is the input numeric?
	if(is.numeric(celsius)){
		result <- celsius * 1.8 + 32
	# if it is not the result should be missing
	}else
		message("Non-numeric input, returning NA!")
		result <- NA
	}
	return(result)
}