# GeoGebra

## User:Barbperez

Barbara Perez

Mathematics Teacher

Cypress Bay High School Weston, FL 33332

## Contents

### Area

created by Barbara Perez

### Angle Relationships/Properties of Parallel Lines

created by Barbara Perez

### Polygon Angle Relationships

created by Barbara Perez

### Ideas for Geometry Worksheets

• Triangle Inequalities

This worksheet will allow students to discover the relationships among the measures of sides and angles in a triangle.

The triangle will be resizable at each vertex, the side lengths and angle measures will be displayed. The sums of all combinations of the two sides will also be calculated and displayed.

• Area of Parallelograms

This worksheet will show why the area of a parallelogram is calculated using the same formula as a rectangle.

The parallelogram will contain two other polygons, a trapezoid and a triangle. The triangle will be able to be translated along the figure to show that it forms a rectangle.

• Area of Trapezoid

This worksheet will demonstrate how the area of a trapezoid is computed .

The trapezoid will contain another identical trapezoid which can be rotated to show that they form a rectangle with a base formed by the sum of the bases, The questions will lead to the student writing the area formula for a trapezoid.

• Similar Polygons

This worksheet will show how the side lengths of similar polygons are proportional.

There will be a polygon and a dilated image of the polygon. The students will be able to manipulate the scale factor. The side lengths will be displayed for both polygons and the questions will lead to the students discovery that the sides are proportional.

• Proportions with Area

This worksheet will allow students to discover the relationship between changes in side length and changes in area.

There will be a polygon and a dilated image of the polygon. The students will be able to manipulate the scale factor. The side lengths and the areas will be displayed for both polygons. The ratio of corresponding sides and areas will also be computed and displayed

### Ideas for GeoGebra Materials

Geometry

• Properties of Parallel Lines and Angle Relationships
• Properties of Triangles
• Properties of Polygons
• Triangle Congruency Tests
• Points of Concurrency
• Pythagorean Theorem
• Scaling
• Properties of Circles
• Transformations