kotlin does wrong equations. it does not calculate correctly

fun main(args: Array<String>) {
    val pie = 22/7
    println("Enter a number for triangle area")
    val input = readLine()?: ""
    val a = input.toInt() * input.toInt()  * pie
    println(a)
}

here when I input 6 it should give us 113.142857143 or 113.14

Instead, it gives 108

output

and with javascript it's fine

js output

It treats the pie as an integer. After rounding the pie will become 3, so 6 * 3 * 3 is 108.

There are numbers of ways to solve this but I recommend using BigDecimal to calculate decimals.

fun main(args: Array<String>) {
    val pie = BigDecimal.valueOf(Math.PI) // Either Math.PI or 22/7, one is 3.1415 another is 3.1428
    println("Enter a number for triangle area")
    val input = readLine()?: "0" // PLEASE DO INPUT VALIDATION HERE
    val inputDecimal = BigDecimal(input)
    val a = inputDecimal.multiply(inputDecimal).multiply(pie)
    println(a)
}