# Activities

• • • ##### Subject Area

• Math: Geometry: Analytic Geometry
• Math: Algebra I: Equations and Inequalities
• Math: Algebra I: Linear Functions
• Math: Algebra I: Rational Functions
• Math: Geometry: Points, Lines and Angles
• Math: Geometry: Reasoning
• Math: Geometry: Triangles

• ##### Author 9-12
College

90 Minutes

• ##### Device
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

• ##### Report an Issue

Slope/Triangle Area Exploration

#### Activity Overview

Using multiple representations afforded by the TI-Nspire and TI-Nspire CAS, students investigate the following problem (Adapted from Philips Exeter Academy, 2007).

The equation y − 5 = m (x − 2) represents a line, no matter what value m has.
(a) What are the x- and y-intercepts of this line?
(b) For what value of m does this line form a triangle of area 36 square units with the positive x- and y-axes?
(c) Describe the areas of the first-quadrant triangles.

#### Before the Activity

You should familiarize yourself with the associated .tns file, the activity guide, and the guided inquiry questions.

#### During the Activity

This document contains the Teacher Guide and Student Questions.