(1)根据三条边可知,最小角为∠c
余弦定理,a^2+b^2-2abcosc=c^2
49+48-56g3cosc=13
cosc=84/56g3=g3/2
所以∠c=30
(2)S=1/2*ab*sinc=1/2*28g3*1/2=7g3
(g是根号)
(1)根据三条边可知,最小角为∠c
余弦定理,a^2+b^2-2abcosc=c^2
49+48-56g3cosc=13
cosc=84/56g3=g3/2
所以∠c=30
(2)S=1/2*ab*sinc=1/2*28g3*1/2=7g3
(g是根号)