If we have two points A(x,y) and B(m,n) We can calculate the length of AB: AB²=(x-m)²+(y-n)². Applying this formula we find out the length of 4 sides A(-6;-3), B(-2;5), C(2;5), and D(6;-3) A and D are symmetry by Oy and the same to B and C. And the trapezoid is ABCD AB²=(-6+2)²+(-3-5)²= 80 and AB=CD=4√5 BC=4, AD=12 the approximate perimeter is AB+BC+CD+AD= 16+4√5= 25
