Why does this accept invalid input?

Question

I have a triangle program in c

#include 

// A function which decides the type of the triangle and prints it
void checkTriangle(int s1, int s         


        

Answer 1

%d accepts only integer. try with %x in scanf() for hex-decimal input.

Better you can get input as string then check using isnumeric() else use scanf("%[^\n]s", word) like @mou suggested.