Plz !
the triangles are similar. the area of the larger triangle is 729 cm².

what is the area of the smaller triangle?
10.5 cm²
31.5 cm²
67 cm²
81 cm²

Corresponding sides have a ratio of 18/54 = 1/3. Thus the area will have a ratio of (1/3)^2 = 1/9.

The smaller triangle has an area of
.. (1/9)*729 cm^2 = 81 cm^2 . . . . . . . . . . . . . . corresponds to the 4th selection

Definitely