Q28 of 168 Page 4

Determine whether the triangle having sides (a – 1) cm, cm and (a + 1) cm is a right angled triangle.

Let ABC be the triangle

Where AB=(a-1)2 cm


BC=2√a cm


CA=(a+1) cm


AB2=(a-1)2=a2+1-2a


BC2=(2√a)2=4a2


CA2=(a+1)2=a2+1+2a


Hence AB2+BC2=AC2


SO ΔABC is a right angles triangle at B


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