Area of a Ground

In a running race, players have to know about the area of the ground. The ground is in trapezium shape. The length of the parallel sides denoted by A and B of the ground and the height H of the ground are given. The program must calculate and print the area of the ground with precision upto 2 decimal places as the output.

Formula: Area of trapezium = ((A + B) * H) / 2

Example Input/Output 1:
Input:
10 15 20

Output:
250.00

Example Input/Output 2:
Input:
5 4 5

Output:
22.5

#include<stdio.h>
#include <stdlib.h>
int main()
{
    int a,b,h;
    scanf("%d %d %d",&a,&b,&h);
    int sum=a+b;
    float c=((sum)*h);
    printf("%.2f",c/2);
}