javascript please help!

Increment \& Decrement Operators 1. Create a variable named ... incrementThis ... and assign it an integer or double value. Then increment the variable by one using an increment operator. Display the result to the Console. 2. Now decrement the variable by one using an increment operator. Display the result to the Console. Math.PI FYI, Math.PI is a defined value for the Math class that can be assigned to a variable or constant, i.e. double myVar = Math. P; 1. Create a constant that assigns the value of ...PI... using Math.PI. 2. Add a calculation of a circle's perimeter using the formula 2R, where ...R... is the radius of the of the circle with the value of. .7cm. Example: Radius of 4cm.C=2R =2constant(PI)4=25.12cm 3. Display the result to the Console