Answer:
She will need 4 square and 8 triangular pieces.
Explanation:
For every 6 pieces of cloth, 2 are squares.
So, for 12 pieces of cloth, the no. of square pieces would be,

=

= 4
As the remaining pieces will be triangles, so the no. of triangular pieces will be, equal to,
(12 - 4) = 8