-----Description----- 
This task requires writing a Lean 4 method that finds the kth element in a given array using 1-based indexing. The method should return the element at the specified position, where the first element is at position 1.

-----Input-----
The input consists of:
arr: An array of integers.
k: An integer representing the position (1-based index) of the element to find.

-----Output-----
The output is an integer:
Returns the element at the kth position in the array.

-----Note-----
The input k is assumed to be valid (between 1 and array length inclusive).
The array is assumed to be non-empty.