Identities Concept Instruments (a+b+c)2 This identities is provided with magnet at back to demonstrate on magnetic board. (Measure Size 41x41 cm) (a+b)2-(a-b)2=4ab This identity is provided with magnet at back to demonstrate on magnetic board. Measure Size 41X41 cm. (a+b)3 This is a demonstration model of (a+b)3. Made up of plastic easy to show the complex identity by detachable set of 8 piece.