Answer:
240 cm^2
Step-by-step explanation:
area of each triangle
=(10 x 7)/2 cm^2
=35 cm^2
area of four triangles
=35 x 4 cm^2
=140 cm^2
area of the square
=10 x 10 cm^2
=100 cm^2
area of the polygon
=(100 + 140) cm^2
=240 cm^2
