Sure! Below is an example of how to implement a basic CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) in an Angular 9 application using a simple math-based CAPTCHA.

1. Setting up the Angular 9 Project:

Make sure you have Node.js and Angular CLI installed. If not, install them using the following commands:

```bash

npm install -g @angular/cli

```

Now, create a new Angular project:

```bash

ng new angular-captcha-example

cd angular-captcha-example

```

2. Creating the CAPTCHA Component:

Generate a new component called `captcha`:

```bash

ng generate component captcha

```

3. Implementing the CAPTCHA Logic:

Open the `captcha.component.ts` file and implement the CAPTCHA logic:

```typescript

import { Component, OnInit } from '@angular/core';

@Component({

selector: 'app-captcha',

templateUrl: './captcha.component.html',

styleUrls: ['./captcha.component.css']

})

export class CaptchaComponent implements OnInit {

captchaValue: string = '';

userResponse: string = '';

isCaptchaValid: boolean = false;

constructor() { }

ngOnInit(): void {

this.generateCaptcha();

}

generateCaptcha(): void {

const num1 = Math.floor(Math.random() 10);

const num2 = Math.floor(Math.random() 10);

this.captchaValue = `${num1} + ${num2}`;

}

checkCaptcha(): void {

const [num1, , num2] = this.captchaValue.split(' ');

const expectedResult = Number(num1) + Number(num2);

const userResult = Number(this.userResponse);

this.isCaptchaValid = expectedResult === userResult;

this.generateCaptcha();

this.userResponse = '';

}

}

```

4. Creating the CAPTCHA Template:

Open the `captcha.component.html` file and add the following template:

```html