https://www.codecademy.com/en/courses/spencer-sandbox/5/4

When I run my code, it works beautifully. However, I receive the following error message:

`Oops, try again. Your perimeter method fails on a Circle with radius 1 where it returns τ when it should return 6.283185307179586`

Now, I know this is Codecademy's SCT thinking that I've returned the wrong value. But I haven't, 6.283185307179586... is the constant known as tau. The symbol for tau is `τ`

. I returned the correct value and the SCT doesn't care. This code works, but because the SCT doesn't recognize `π`

and/or `τ`

as values, my code is considered incorrect. What's up with that?

```
var pi = Math.PI;
var tau = (pi * 2);
var circles = new Array();
function Circle (radius) {
this.radius = radius;
this.area = function () {
var area = (pi * this.radius * this.radius);
if (area == pi) {
return "π";
} else if (area == tau) {
return "τ";
} else {
return area;
};
};
this.perimeter = function () {
var perimeter = (2 * pi * this.radius);
if (perimeter == pi) {
return "π";
} else if (perimeter == tau) {
return "τ";
} else {
return perimeter;
};
};
};
for (i = 1; i <= 10; i++) {
circles[i - 1] = new Circle(i);
};
for (i = 0; i < circles.length; i++) {
console.log("I am a circle with a radius of " + (i + 1) + ", a perimeter of " + circles[i].perimeter() + ", and an area of " + circles[i].area() + ".");
};
```