Area of Triangle using SideAngleSide (length of two sides and the included angle) (original) (raw)
Last Updated : 19 Dec, 2021
Given two integers A, B representing the length of two sides of a triangle and an integer K representing the angle between them in radian, the task is to calculate the area of the triangle from the given information.
Examples:
Input: a = 9, b = 12, K = 2
Output: 49.1
Explanation:
Area of triangle = 1 / 2 * (9 * 12 * Sin 2) = 35.12
Input: A = 2, B = 4, K = 1
Output: 3.37
Approach:
Consider the following triangle ABC with sides A, B, C, and an angle K between sides A and B.

Then, the area of the triangle can be calculated using the Side-Angle-Side formula:
Area (ABC) = \frac{1}{2} \ A * B * sin(K)
Below is the implementation of the above approach:
C++ `
// C++ program to calculate // the area of a triangle when // the length of two adjacent // sides and the angle between // them is provided #include <bits/stdc++.h> using namespace std;
float Area_of_Triangle(int a, int b, int k) { float area = (float)((1 / 2.0) * a * b * (sin(k)));
return area; }
// Driver Code int main() { int a = 9; int b = 12; int k = 2;
// Function Call
float ans = Area_of_Triangle(a, b, k);
// Print the final answer
cout << ans << endl;}
// This code is contributed by Ritik Bansal
Java
// Java program to calculate // the area of a triangle when // the length of two adjacent // sides and the angle between // them is provided class GFG{
// Function to return the area of // triangle using Side-Angle-Side // formula static float Area_of_Triangle(int a, int b, int k) { float area = (float)((1 / 2.0) * a * b * Math.sin(k));
return area;}
// Driver Code public static void main(String[] args) { int a = 9; int b = 12; int k = 2;
// Function Call
float ans = Area_of_Triangle(a, b, k);
// Print the final answer
System.out.printf("%.1f",ans);} }
// This code is contributed by sapnasingh4991
Python3
Python3 program to calculate
the area of a triangle when
the length of two adjacent
sides and the angle between
them is provided
import math
Function to return the area of
triangle using Side-Angle-Side
formula
def Area_of_Triangle(a, b, k):
area =(1 / 2) * a * b * math.sin(k)
return area Driver Code
a = 9 b = 12 k = 2
Function Call
ans = Area_of_Triangle(a, b, k)
Print the final answer
print(round(ans, 2))
C#
// C# program to calculate // the area of a triangle when // the length of two adjacent // sides and the angle between // them is provided using System; class GFG{
// Function to return the area of // triangle using Side-Angle-Side // formula static float Area_of_Triangle(int a, int b, int k) { float area = (float)((1 / 2.0) * a * b * Math.Sin(k));
return area;}
// Driver Code public static void Main(String[] args) { int a = 9; int b = 12; int k = 2;
// Function Call
float ans = Area_of_Triangle(a, b, k);
// Print the readonly answer
Console.Write("{0:F1}", ans);} }
// This code is contributed by sapnasingh4991
JavaScript
`
Time Complexity: O(1)
Auxiliary Space: O(1)