A square with an area of 1 square meter is decomposed into 9 identical small squares. Each small square is decomposed into two identical triangles.
1 square meter is decomposed into 9 identical small squares
So there are 9 small squares in 1 square meter.
Each small square is decomposed into two identical triangles
So 9 small squares is decomposed into 9*2=18 identical triangles
Hence, 1 square meter is decomposed into 18 identical triangles.
WE need to find number of triangles are needed to compose a region that is
square meters
square meters = 1.5 square meters
1 square meter = 18 identical triangles.
1.5 square meters = 1.5 * 18 = 27 identical triangles.
There are 27 triangles are needed to compose a region that is 1 1/2 square meters.