Name: carissa

Who is asking: Student
Level: Secondary

How do you : Triangle ABC is right-angled at A. Calculate the length of the third side if b = 3 and c = 6, express the answer as a surd in its simplest form.

Hi Carissa,

Draw a diagram.

The Theorem of Pythagoras says that, in a right angled triangle, the square of the hypotenuse is the sum of the squares of the other two sides. I this triangle the side BC is the hypotenuse and thus

|BC|2 = 32 + 62 = 9 + 36 = 45

|BC| = Sqrt(45)
Express Sqrt(45) in its simplist form.

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