For this case we have:
Let x be the variable that belongs to the real numbers. Then, all reals less than 70 can be expressed as:

The tip of the inequality is directed to the real numbers, since they tell us that they are less than 70, for 70 the inequality remains open.
Answer:

Answer:
Area: (3+√7) x (1+2√7) = 17+7√7 = 35.52
Perimeter: 2(3+√7) + 2(1+2√7) = 8+6√7 = 23.87