Intr-un paralelogram ABCD m(A)=3/7×m(B)
m(C)=?


Răspuns :

ABCD = paralelogram → 2A+2B = 360° → A + B = 180° → B + 3/7B = 180°; 10B = 180 x 7 → B = 126°. B + C = 180° → C = 54°