This rectangle is a square

Earlier this year, my nephew visited from overseas with his Maths holiday homework. He was on summer holidays between years 8 and 9. This is one of the questions I can translate:

Show that a rectangle ABCD, such that AB=√125 and BC=3√45 - 2√20 is a square.

You could post your answer in the comments field or try it with your students and post their answers instead.

Elias.

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Comments

Anonymous said…
In my Algebra 2 class, we are currently reviewing how to simplify radical expressions so that we can properly present the solutions to quadratic equations. So, today I'll present them with this nice little problem.

I'll post their results soon.
9:27 pm
Anonymous said…
Here are proofs from four of my students in my 9th grade Algebra 2 class.

Proof 1
Proof 2
Proof 3
Proof 4
11:57 am
Rambling Teacher said…
Thank you so much, Mr. B. These are fabulous specimen of work done by well taught students. Compliments to the teacher.

Elias.
2:38 pm
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