Sal Khan offers from basic to advanced area and perimeter problems, which will later be introduced throughout this textbook. In Chapter 1, the textbook covers basic area and perimeter of triangle, rectangle, and circles. Watch the following videos and practices for more help with area and perimeter in Chapter 1.
Video - Perimeter and area basics
Practice -Area of triangles
Video - Circles: Radius, diameter, and circumference
Video - Parts of a circle
Practice - Radius, diameter, and circumference
Video - Area of a circle
Practice - Area of a circle