Science, Tech, Math Math Calculating Area - A Primer Share Flipboard Email Print Math Math Formulas & Math Tables Basics Tutorials & Courses Arithmetic Geometry Pre Algebra & Algebra Statistics Exponential Decay Functions Worksheets by Grade Resources View More by Deb Russell Deb Russell is a school principal who has taught mathematics at all levels. She is also a freelance writer with more than 14 years of experience. Updated March 17, 2017 Understanding how to calculate area is important to understand at the early age of 8-10. Calculating area is a pre-algebra skill that should be well understood prior to beginning algebra. Students by grade 4 need to understand the early concepts of calculating the area of a variety of shapes. Formulas for calculating area use letters which are identified below. For example the formula for the area of a circle will look like this: A = π r 2 This formula means that the area is equal to 3.14 times the radius squared. The area of a rectangle would look like this: A = lw This formula means that the area of the rectangle is equal to the length times the width. Area of a triangle - A= ( b x h ) / 2. .( See Image 1). To best understand the area of a triangle, consider the fact that a triangle forms 1/2 of a rectangle. To determine the area of a rectangle , we use length times width ( l x w ). We use the terms base and height for a triangle, but the concept is the same. (See Image 2 ). Area of Sphere - ( the surface area ) The formula is 4 π r 2 For a 3-D object the 3-D area is termed as the volume.Area calculations are used in many sciences and studies and have practical daily uses such as determining the amount of paint required to paint a room. Recognizing the various shapes that are involved is essential to calculating area for complex shapes. (See images) Continue Reading