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horca.js

let listaPalabras = ["ALURA", "JAVASCRIPT", "FAMILIA", "HOGAR", "CONFIANZA"];
let tablero = document.getElementById("horca").getContext("2d");
let palabraSecreta = "";

function sortearPalabraSecreta() {
    let palabraSorteada = listaPalabras[Math.floor(Math.random() * listaPalabras.length)];
    palabraSecreta = palabraSorteada;
    console.log(palabraSecreta);
}

function iniciarJuego(){
    document.getElementById("iniciar-juego").style.display = "none";

    sortearPalabraSecreta()
    dibujarCanvas()
}

canvas.js

function dibujarCanvas() {
    tablero.lineWidth = 8;
    tablero.lineCap = "round";
    tablero.lineJoin = "round";
    tablero.fillStyle = "#41d0d0"
    tablero.strokeStyle = "#8A3871";

    tablero.fillRect(0,0,1200,860);
    tablero.beginPath();
    tablero.moveTo(650,500);
    tablero.lineTo(900,500);
    tablero.stroke();
    tablero.closePath();

}

juego.html

<!doctype html>
<html>
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Jurgo del ahorcado - Alura</title>
        <link rel="stylesheet" href="reset.css">
        <link rel="stylesheet" href="style.css">
        <link href="https://fonts.googleapis.com/css2?family=Montserrat:wght@300&display=swap" rel="stylesheet">
    </head>
    <body>
        <img src="imagenes/logo.png" class="logo">
            <div id="div-desaparece-boton" class="botones-home">
                <a href="#horca">
                <input class="boton-iniciar" type="submit" value="Iniciar Juego" id="iniciar-juego" onclick="iniciarJuego()">
                </a>
            </div>
        <div id="div-aparece-ahorcado" class="canvas">
            <canvas id="horca" width="1200" height="860"></canvas>

            <div class="subrayado">
            </div>
        </div>

    <script src="horca.js"></script>
    <script src="canvas.js"></script>
    </body>
</html>