How to Implement a javascript solution to calculate the total length of iron bars required to create a gate?

Please help me to solve this problem,

Implement a javascript app that can calculate the total length of iron bars required to create a gate
. The gate will have an alternating design of empty rows and rows filled with circles (please note the design starts with an empty row from top). Design should be symmetrical. If a symmetrical design cannot be generated for given inputs, the programme should identify and show a message to the user.

Note:

Bar will have a thickness of 10cm;
Take this value into account when doing calculations.
Minimise the waste of bars as much as possible.

Inputs:

width and height of gate (in cm)
Max height percentage of each row (ex. If the gate height is 100cm and the max row height is 10%, then each row can be a max 10cm in height).

This is the code block.

function calculateTotalBarLengthReq(gateWidth, gateHeight, rowHeightPercentage, barThickness) {
  return false;
}

const ironBarThickness = 10;
calculateTotalBarLengthReq(500, 500, 20, ironBarThickness);

The answer should be 7021.59cm.

I tried to calculate the total length of iron bars required to create a gate.

Please apply below logic and check

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

function calculateTotalBarLengthReq(gateWidth, gateHeight, rowHeightPercentage, barThickness) {
// Calculate the length of vertical bars (columns)
const verticalBarLength = gateHeight * 2;

// Calculate the size of each row
const rowSize = gateHeight * rowHeightPercentage * 0.01;

// Calculate the number of horizontal bars (rows)
const numOfHorizontalBars = (gateHeight / rowSize) + 1;

// Calculate the length of horizontal bars
const horizontalBarLength = (gateWidth - barThickness * 2) * numOfHorizontalBars;

// Calculate the gap between rows
const rowGap = (gateHeight - numOfHorizontalBars * barThickness) / (numOfHorizontalBars - 1);

// Calculate the number of circles in a row
const numOfCirclesInRow = gateWidth / rowGap; //this may not natural number (float value)
// const numOfCirclesInRow = Math.floor(gateWidth / rowGap); // this will give natural number (integer value)

// Calculate the number of alternate rows with circles
const numOfRowsWithCircles = Math.floor((numOfHorizontalBars - 1) / 2);

// Calculate the total number of circles
const totalNumOfCircles = numOfCirclesInRow * numOfRowsWithCircles;

// Calculate the radius of each circle
const radius = rowGap / 2;

// Calculate the circumference of each circle
const circumference = 2 * radius * Math.PI;

// Calculate the total length of iron bars required
const totalBarLength = verticalBarLength + horizontalBarLength + circumference * totalNumOfCircles;

return Total bar length requirement = ${totalBarLength.toFixed(2)}cm;
}

const ironBarThickness = 10;
console.log(calculateTotalBarLengthReq(500, 500, 20, ironBarThickness));
console.log(calculateTotalBarLengthReq(100, 100, 20, ironBarThickness));
<!-- end snippet -->

Note: From your example, when calculating to get desired output 7021.59, number of circles in a row is not considered as a natural number (here it is 5.68). So, if you want to change the logic to take the number of circles in a row as natural number (that is 5) which gives output 6644.60. Then, take the commented calculation of numOfCirclesInRow