Retaining wall of 6 meter height having a smuth back retaines back fill made up of to stractuer ,construct the active earth pressure deagram and fined the magnitude and point of application of the resultant thrust assume the back fill above water table remains dry

In a unit cell of fcc structure, indicate the position of one of the tetrahedral interstitial sites by plotting the corresponding tetrahedron. do the same for one of the octahedral interstitial sites (in a separate fcc unit cell). mark the positions of all the tetrahedral and octahedral interstitial sites in the unit cells. how many equivalent tetrahedral sites and how many equivalent octahedral sites are contained in a fcc unit cell, respectively. what is the coordination number for a tetrahedral site and what is the coordination number for an octahedral site?