express the area and perimeter of an equilateral triangle as a function of the triangle side length x
a function for the area of an equilateral triangle is A(x)=sqrt(x*x2)/4
Welcome to the forum.
There are several ways to get to the area answer. eg. If you can work out AD in my diagram then you can do half base times height.
Do you know Pythagoras' theorem ?
As for the perimeter, that should be straight forward as all the sides are equal.
When you post again, I will be able to see how much help you need.