The rectangular prism is to be sliced perpendicular to the shaded face and is to pass through point B, parallel to the front face. What will the dimensions of the rectangular cross section be? A rectangular prism. The rectangular base has a length of 10 centimeters and width of 8 centimeters. The rectangular side with point B has a length of 10 centimeters and width of 18 centimeters. 8 centimeters by 18 centimeters 8 centimeters by 10 centimeters 10 centimeters by 18 centimeters 4 centimeters by 18 centimeters