## Introduction

The C# programming language is a versatile and powerful tool for developing a wide range of applications. One common task in programming is to create a trigonometry calculator. In this article, we will explore how to implement a trigonometry calculator in C# with examples.

## Getting Started

Before we dive into the code, let’s first understand the basic concepts of trigonometry. Trigonometry is a branch of mathematics that deals with the relationships between the angles and sides of triangles. It is widely used in various fields such as physics, engineering, and computer graphics.

## Calculating Trigonometric Functions

In C#, the Math class provides built-in functions to calculate common trigonometric functions such as sine, cosine, and tangent. These functions take an angle in radians as input and return the corresponding trigonometric value.

```
using System;
class TrigonometryCalculator
{
static void Main()
{
double angle = 45; // Angle in degrees
// Convert angle to radians
double radians = angle * Math.PI / 180;
// Calculate sine
double sine = Math.Sin(radians);
Console.WriteLine("Sine: " + sine);
// Calculate cosine
double cosine = Math.Cos(radians);
Console.WriteLine("Cosine: " + cosine);
// Calculate tangent
double tangent = Math.Tan(radians);
Console.WriteLine("Tangent: " + tangent);
}
}
```

In the above example, we start by defining the angle in degrees. We then convert the angle to radians using the formula angle * Math.PI / 180. This is necessary because the trigonometric functions in C# expect angles in radians.

We then use the Math.Sin, Math.Cos, and Math.Tan functions to calculate the sine, cosine, and tangent of the angle, respectively. Finally, we print the results to the console.

## Handling Invalid Inputs

It is important to handle invalid inputs when creating a trigonometry calculator. For example, if the user enters an angle that is not within the valid range, the calculator should display an error message.

```
using System;
class TrigonometryCalculator
{
static void Main()
{
double angle = -90; // Invalid angle
if (angle >= -90 && angle <= 90)
{
double radians = angle * Math.PI / 180;
double sine = Math.Sin(radians);
Console.WriteLine("Sine: " + sine);
double cosine = Math.Cos(radians);
Console.WriteLine("Cosine: " + cosine);
double tangent = Math.Tan(radians);
Console.WriteLine("Tangent: " + tangent);
}
else
{
Console.WriteLine("Invalid angle!");
}
}
}
```

In the above example, we check if the angle is within the valid range of -90 to 90 degrees. If it is, we proceed with the calculations as before. Otherwise, we display an error message.

## Conclusion

In this article, we have explored how to create a trigonometry calculator in C#. We have learned how to use the Math class to calculate common trigonometric functions and how to handle invalid inputs. By understanding these concepts, you can now apply them to create more complex trigonometry calculators or integrate trigonometric calculations into your own applications.