3:32 Surface Area of a Cuboid - Corbettmaths
Corbettmaths clearly shows how to add up all six faces of a cuboid.
Surface area of a cuboid
Calculate the surface area of a cuboid
2 hand-picked video lessons for this topic, each checked for relevance and clarity, graded by difficulty and labelled by depth. Press play to watch — nothing loads from YouTube until you do.
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11:28 Volume and Surface Area of Cuboids - GCSE Maths
Full method plus four exam-style questions on cuboid surface area.