38, 24, and 12+x.

Question

What is the missing number to make an acute triangle

Answer 1

In order to form an acute triangle, the sum of the two smaller sides must be greater than the third side.

Let's assume the missing number is x.

Considering 38 and 24 as the two smaller sides:

38 + 24 > 12 + x
62 > 12 + x
50 > x

So, to form an acute triangle, x must be less than 50.