Area Calculation Javascript

function areaOfCircle(radius) { 
     return Math.PI * Math.pow(radius, 2); 
}

function areaOfRectangle(width, height) { 
     return width * height; 
}

function areaOfSphere(radius) {
     return 4 * Math.PI * (Math.pow(radius, 2));  
}

function areaOfTriangle(baseWidth, height) { 
      return baseWidth * height / 2;
}