Bài 2: VIC′A′J=1/3.d(I,(C′A′J)).SC′A′Jd(I, (C'A'J))= AA'= 2aSC′A′J=1/2.C′J.A′J=1/2.a√32.a/2=a√38
Bài 2:
VIC′A′J=1/3.d(I,(C′A′J)).SC′A′Jd(I, (C'A'J))= AA'= 2a$S_{C'A'J}= 1/2. C'J. A'J= 1/2. \frac{a\sqrt{3}}{2}. a/2= \frac{a
^{2}\sqrt{3}}{8}$
=> VIC′A′J= a3.√312