Use a Drawing to Help Explain Why $\frac { 3 } { 4 } \times \frac { 5 } { 7 }$

Essay

Use a drawing to help explain why $\frac { 3 } { 4 } \times \frac { 5 } { 7 }$
is equal to $\frac { 3 \times 5 } { 4 \times 7 }$
. Be explicit.