An equilateral triangle measuring 8s feet on a side is changed by decreasing the length of one side by 5 feet and increasing the lengths of the other two sides by 3 feet. what is rhe new perimeter?

We have three sides
a = 8
b = 8
c = 8
The old perimeter is a+b+c = 8+8+8 = 24 feet



Decrease one side, let's say side 'a', by 5 ft
a-5 = 8-5 = 3
Let's call this m, so m = 3

Then increase side b by 3 ft
b+3 = 8+3 = 11
Let's call this n, so n = 11

The same thing will happen to c. The side c will increase to 11, which we'll call p. So p = 11

The old triangle with sides a = 8, b = 8, c = 8 had a perimeter of 24 
The new triangle with sides m = 3, n = 11, p = 11 has a perimeter of 25 (because m+n+p = 3+11+11 = 14+11 = 25)

The perimeter has increased by 1 (because 25-24 = 1)