Help me PLEASE quick I will give you brainliest

Answer:
56. Someone correct me if I'm wrong.
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean Theorem, which is a² + b² = c²
a and b are the legs, and c is the hypotenuse. Here, we know the length of one leg and the hypotenuse. So...
a² + 42² = 70²
First, we need to square these numbers. 42² is 1764. 70² is 4900. So...
a² + 1764 = 4900
Now, we can subtract 1764 from both sides.
a² + 1764 - 1764 = 4900 - 1764
That would give us...
a² = 3136
Now, we square root 3136.
So...
[tex]\sqrt{3136}[/tex] = 56
The missing side should be 56.