Final answer:
The sagittal plane divides the body into right and left portions, with the midsagittal plane creating equal halves.
Step-by-step explanation:
The plane that divides the body into right and left portions is known as the sagittal plane. Specifically, when this plane runs directly through the midline of the body, creating equal right and left halves, it is called a midsagittal or median plane. In contrast, a parasagittal plane would divide the body into unequal right and left portions. Another related plane is the frontal plane (also known as the coronal plane), which divides the body into anterior (front) and posterior (rear) portions.