all of the quadrilaterals in the shape below are squares. find the area of the shaded region.

Explanation:

Step1: Find side - length of large square

The side - length of the large square is 15 units. So its area $A_{1}=15\times15 = 225$ square units.

Step2: Find area of non - shaded small square

The side - length of the non - shaded small square is 10 units. So its area $A_{2}=10\times10 = 100$ square units.

Step3: Find area of shaded region

The area of the shaded region $A = A_{1}-A_{2}$. Substitute $A_{1}=225$ and $A_{2}=100$ into the formula, we get $A=225 - 100=125$ square units.

Answer:

125