perimeter

The ‘TearOut’ series is back, with perimeter and area. Pages 1 and 2 are a worksheet for students, while pages 3 and 4 give guidelines for the facilitator. This time we explore shapes with given perimeter or given area using the dots or the grid.

I write this to tell myself that it was not a dream...

This year I taught a bunch of fifth standard kids in Sahyadri School KFI (Krishnamurti Foundation India), who, like all others of their age, were high-energy kids; they were willing to explore but found it difficult to sit down in one place. I had a great relationship with them. The air in the classroom was of love, trust and wonder!

LinkedIn reader Peter Lovasz asks: Among all triangles that share a given circle as incircle, which one has the smallest perimeter?

Fagnano’s Problem: In 1775, Giovanni Fagnano posed and solved the problem - “For a given acute angled triangle, determine the inscribed triangle of minimum perimeter.” Using calculus, Fagnano showed the solution to be the Orthic Triangle – a triangle formed by the feet of the three altitudes. A different proof was given in At Right Angles, Vol. 6, No.

The topic of Perimeter and Area provides rich ground for teachers to examine the truth values of statements and then introduce the crucial ‘What-If ’ which can change a situation around completely.

This article is the second in the ‘Inequalities’ series. We prove a very important inequality, the Arithmetic Mean-Geometric Mean inequality (‘AM-GM inequality’) which has a vast number of applications and generalizations. We prove it using algebra as well as geometry

Since they are introduced together, one frequently finds children mixing up the two concepts. Also formulae for arriving at these measures are brought in too quickly - well before the concepts are fully understood. One can avoid this problem by spacing out these two concepts. Area could be explored in the first stage as it occurs frequently in a child's everyday experiences.

In a previous issue of AtRiA (as part of the “Low Floor High Ceiling” series), questions had been posed and studied about polyominoes. In this article, we consider and prove two specific results concerning these objects, and make a few remarks about an open problem.

In mathematics, breaking up is not hard to do!

Mr. Jagirdar finally puts to use what he had memorized: the conditions for the nature of the roots of a quadratic!

Pages

17581 registered users
6684 resources