It's b because you have to round up
Answer:
43cm
Step-by-step explanation:
use the pythagorean theorem:
a² + b² = c²
25² + 35² = c²
625 + 1225 = c²
1850 = c²
√1850 = c
43 cm = c
your a, b and c values depend on where the values are on the triangle.
The answer is the option d, which is: d) 
The explanation for this problem is shown below:
1. Smplify the denominator and rewrite the numerator in this form:

2. Multiply the denominator and the numerator by the conjugated
and simplify the expression, as following:

3. As you can see, you obtain the expression shown in the option mentioned above.