I need help to fix the error on this C code, the instruction was to not include a main function in the source file, so I put the main function in the header file, but I'm having an error.

is Ealt Selection Fnd Viaw Goto Tools Project Preserences Hedp 1) wold findadjacentPy th (double a, double c, double x, dowble y ); votd findlypotcnuselirig(double 1 , double 11, double d, double d1); vold findHypotenuseryyth(double 1 , double 11 , double d, double d1); noid findadjacent Trighouble i2 duble d2 dubble d1, double d2); rodd find0ppositePyth(double 1, double d, double d1, double d2); int nand) findad jacentPyth ( 97, 129.6341694526, 0.8454352154,0.7253611114) find0ppositePyth (62,86.9770984563,0.7772682612,0.7935289656); findHypotenusePyth( 77,78,0.778946646020.7918496868); J E. Jre i. Counn 3