Binomial expansion using Pascal's Triangle Geometry was the main objective of this lesson. The binomial expansion of (a+b)^5 was done using the binomial coefficients in Pascal's Triangle. The fifth row of Pascal's Triangle was used to create the binomial theorem formula for the binomial expansion of (a+b)^5. This lesson on the binomial expansion is suitable for a level maths, grade 12 maths and Engineering mathematics students. It also serves as a precalculus lesson for further topics in calculus. Questions that were answered in this binomial expansion lesson are how do expand binomials, How to do binomial expansion, how to expand binomials using Pascal's Triangle, what is binomial expansion, what is Pascal's Triangle and what are binomial coefficients.