Pointer error in two lines of code

Hi everyone,
I'm typing up a program that allows the input of the radius and height of a cylinder and outputs the total surface area, lateral surface area, and volume of the cylinder. I've typed up the skeleton of the program and I'm just fixing up errors but I can't figure this one out. (The errors are pointed out to the right of the lines through comments in the bottom half of the program)

#include <iostream>
#include <cmath>
using namespace std;

double totalSurfaceArea(double r, double h);
double lateralSurfaceArea(double r, double h);
double volume (double r, double h);

int main()
{
double r, h;
double tArea, lArea, v;
const double PI = 3.14159265;

cout << "This program will calculate the total surface area, lateral surface area, and volume of a right-circular cylinder. \n Please enter the radius and height of the cylinder. \n";
cin >> r >> h;

tArea = totalSurfaceArea (r, h);
lArea = lateralSurfaceArea (r, h);
v = volume (r, h);

cout << "The total surface area is: " << tArea << "; the lateral surface area is: " << lArea << "; and the volume is " << v << ".";

std::cin.clear();
std::cin.ignore();
getchar();
return 0;
}
const double PI = 3.14159265;
double totalSurfaceArea (double r, double h)

{
double tArea;

tArea = 2*PI*r(r+h); //error is in the first r

return tArea;

}

double lateralSurfaceArea (double r, double h)
{
double lArea;

lArea = 2*PI*r*h;

return lArea;

}

double volume (double r, double h)
{
double v;

v = PI(pow(r,2))*h; //error is in the PI

return v;

}

The type of error is "term does not evaluate to a function taking 1 argument" in both cases, and if I hover over the 'r' or 'PI' the error says "expression must have (pointer-to-) function type." I am something of a novice programmer
in C++, so using simple terms is most helpful. Thanks in advance.
p.s. Apologies for the poor format copy/paste has left you)

r is a double, not a function. See how you're using the asterisk to indicate multiplication? You need to do that consistently. Parens are used to call functions, not to indicate multiplication.

Thank you for your help! I've got the program running now.