Bài 2: $V_{IC'A'J}= 1/3. d(I, (C'A'J)).S_{C'A'J}$d(I, (C'A'J))= AA'= 2a$S_{C'A'J}= 1/2. C'J. A'J= 1/2. \frac{a\sqrt{3}}{2}. a/2= \frac{a^{2}\sqrt{3}}{8}$=> $V_{IC'A'J}$= $\frac{a^{3}.\sqrt{3}}{12}$
Bài 2: $V_{IC'A'J}= 1/3. d(I, (C'A'J)).S_{C'A'J}$d(I, (C'A'J))= AA'= 2a$S_{C'A'J}= 1/2. C'J. A'J= 1/2. \frac{a\sqrt{3}}{2}. a/2= \frac{a\sqrt{3}}{8}$
Bài 2: $V_{IC'A'J}= 1/3. d(I, (C'A'J)).S_{C'A'J}$d(I, (C'A'J))= AA'= 2a$S_{C'A'J}= 1/2. C'J. A'J= 1/2. \frac{a\sqrt{3}}{2}. a/2= \frac{a
^{2}\sqrt{3}}{8}$
=> $V_{IC'A'J}$= $\frac{a^{3}.\sqrt{3}}{12}$