so you are going to use the Pythagorean theorem on the smaller triangle to find the connecting side's length

now you can find the bigger triangle's hypotenuse

c=4
Here’s the prime numbers on one dice: 2 3 5, so 3/6. If you have two die then your answer is 6/12. You have a 50 percent chance of not rolling prime numbers on both.
500.
Solution: 210 is 42% of X
Equation: Y = P% * X
Solving our equation for X
X = Y/P%
X = 210/42%
Converting percent to decimal:
p = 42%/100 = 0.42
X = 210/0.42
X = 500