Answer:
90 square inches.
Explanation:
The total square shape has an area of 100 in but the corners are cut off. The corner is a triangle with the dimension of 5x2. Area for a triangle is 1/2bh so 1/2(5x2)=5. Two corners are cut off so 5x2 is 10. Subtract the triangles from your original square. 100-10=90.