Here are five triangles on a square grid. Four of the triangles have the same area. Which triangle has a different area?
The area of a triangle is half base times height or the base times the height divided by two. Triangle 𝐴 has a base measuring one square and its height is five squares. Five times one is five, divided by two or five halved is 2.5. The base of triangle 𝐵 is one and its height is six. One times six is six and half of that is three.
Triangle 𝐶’s base is two and its height is three. Three times two is six. Half of that is three. The base of triangle 𝐷 is three; its height is two. Three times two is six and half of six is three. And triangle 𝐸 also has an area of three. Its base is two; its height is three. Two times three is six and a half of six is three.
So the triangle which has a different area is triangle 𝐴. It has an area of 2.5 squares. And all the other triangles have an area of three.