What is the almost square rash on the inside of your leg near your knee?

The almost square rash on the inside of your leg near your knee could be caused by several factors, including contact dermatitis, which is a skin reaction to an irritant or allergen. It may also be a fungal infection, such as tinea, or a condition like psoriasis or eczema. If the rash is persistent, itchy, or accompanied by other symptoms, it's important to consult a healthcare professional for an accurate diagnosis and appropriate treatment.