The area of the base is \(5 \times 5 = 25~cm^2\) The area of each triangular face is \((5 \times 6) \div 2 = 15~cm^2\). There are four identical triangular faces, so the total surface area is \(25 ...

A 3D model has been created of a triangular Scottish castle described ... to let people continue to enjoy the building's "pleasing geometry" during lockdown. The castle has been described as ...