Question 9
Mr. Nobi used a square grid paper $ABCD$, as shown in the diagram, to fold an envelope.
Then, he folded it as follows:
1) Fold $D$ to $F$;
2) Fold $E$ to $I$ and $G$ to $K$;
3) Fold $A$ to $M$ and $B$ to $N$;
4) Fold $O$ to $L$ and $P$ to $L$;
5) Fold $Q$ to $R$.
Given that $AB=12$ cm, what is the area, in cm², of the envelope he obtained?
Draw the envelope he obtained.
Then, he folded it as follows:
1) Fold $D$ to $F$;
2) Fold $E$ to $I$ and $G$ to $K$;
3) Fold $A$ to $M$ and $B$ to $N$;
4) Fold $O$ to $L$ and $P$ to $L$;
5) Fold $Q$ to $R$.
Given that $AB=12$ cm, what is the area, in cm², of the envelope he obtained?
Draw the envelope he obtained.