$(46$ pt$.)$ Q$5-$ The Iron $-$ Carbon phase diagram is given in the following Figure. Answer the following questions related to the given figure.

a$)(15$ pt$.)$ Define the terms which are given on the figure;

Region $1,$ R$1$ :

Region $2,$ R$2$:

Region $3,$ R$3$ :

Region $4,$ R$4$:

Region $5,$ R$5$:

Region $6,$ R$6$:

Region $7,$ R$7$:

Point $1,$ P$1$:

Point $2,$ P$2$ :

Point $3,$ P$3$ :

Text $1,$ TEXT $1$ :

Text $2,$ TEXT $2$ :

Text $3,$ TEXT $3$ :

Text $4,$ TEXT $4$ :