[填空题]
A right pyramid has 26i mxs2zp6r+-jleb wapex V and square base ABCqz;58o33 lwecr dmb+ywi7co w2vp ax/1lt(5q D with the base diagonal AC=4cm. The sloping edges are 7 cm long.
8 y5emqcbqp 2o/l7(rwl+o153 awvw; xdct3iz
1.Calculate the size of the angle that sloping edge VC makes with
the pyramid base. ${\circ}$
2.Calculate the vertical height of the pyramid, VO. cm
3.Calculate the volume of the pyramid. $cm^3$