Decompose shapes and check congruence
Show that area stays the same when a shape is cut apart and rearranged, and decide whether two shapes are congruent. Unlimited questions, five difficulty levels, and a full worked solution every time — free.
Try one
A rectangle covers 12 unit squares. It is cut into two pieces along a straight line. One piece covers 3 unit squares. How many unit squares does the other piece cover?
Answer: 9
See one solved, step by step
A shape with an area of 8 unit squares is cut into 2 pieces (2 and 6 unit squares). If you rearrange those 2 pieces into a brand new shape, what is the area of the new shape?
📘 Worked solution
12 + 6 = 8The pieces add up to the same area they started with.
2Answer: 8 unit squaresComposing and decomposing a shape rearranges its parts but never changes the total area.
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