C - Why "a" has the size of an int?

Question

#include <stdio.h>

int main() {
float a = 10.5;
printf("%d %d", sizeof(a), sizeof(10.5));
return 0;
}

Answer 1

Aren't the size of int and float the same.

Answer 2

I just want to add that floating point literals that are defined without a suffix like 'f' are by default treated as double values, therefore the sizes of sizeof( a ) and sizeof( 10.5 ) might differ since 'a' is of type float but 10.5 is of type double.