# NCTM Illuminations Lessons

## Domain Representations

Students use graphs, tables, number lines, verbal descriptions, and symbols to represent the domain of various functions.

## Growth Rate

Given growth charts for the heights of girls and boys, students use slope to approximate rates of change in the height of boys and girls at different ages. Students use these approximations to plot graphs of the rate of change of height vs. age for boys and girls.

## Inequalities in Triangles

Students use pasta to create models of triangles and non-triangles and investigate a relationship between the longest side of the triangle and the sum of the other two sides of the triangle. In addition, students measure the sides and angles of a scalene triangle and investigate a relationship between the location of the largest angle and largest side in a triangle.

## Law of Sines

Students use right triangle trigonometry to develop the law of sines.

## Law of Cosines

Students use right triangle trigonometry and the Pythagorean theorem to develop the law of cosines.

## Successive Discounts

Students examine numeric, algebraic, and graphical representations of compositions of function in the context of successive discounts at a retail store.