The perimeter is twice the sum of the length and the width:

The area is the product of the dimensions:

So, the system is

I believe it’s
D.51is it B ??
60 hope it helps and its right
Answer:
To know that a triangle is right angled triangle we will have to apply pythagoras theorem to verify it
Like length 3, 4 and 5 are leghts of right angled triangle