 # Surf for More Math

## Lesson 7 - Modelling Congruence with Transformations

To encourage students to have fun on the Web while learning about Modelling Congruence with Transformations, here are some games and interactive activities they can do on their own or in pairs.

### Goal

Show congruence using transformations.

### Builds Upon

Student Book pages 398-399

### Instructions for Use

Congruent Triangles prompts students to show congruence using transformations.

To use Congruent Triangles, try all the applets including rotation, translation and reflection. For the rotation applet, rotate a triangle by dragging the red point on the circle. Fit the red triangle exactly on the blue triangle. Move the centre point of the rotation. For the translation applet, drag the head point of the arrow so that the red triangle fits on the blue triangle. For the reflection applet, drag the two end points of the mirror line of reflection. Place the red triangle on the blue triangle.

Congruence in Right Triangles lets students show congruence using transformations.

To use Congruence in Right Triangles click select 'Hypotenuse congruent' under the 'Condition' heading. Name the pair of congruent sides. Drag the vertices of the triangles to form new right triangles. Try to reshape the right triangles so that they are not congruent to each other, even while the hypotenuses are congruent. Click on 'Click to measure lengths' and use the interactive rulers to measure the legs of the triangles.

Under 'Condition', select 'Hypotenuse and one leg congruent'. Drag the vertices of the triangles to form new right triangles. Try to make the triangles not congruent to each other. Use the rulers to compare the lengths of AB and DE. Click on 'Click to measure angles' and use the interactive protractors to measure angles.

Under 'Condition', select 'One leg congruent'. Drag the vertices of the triangles to form new right triangles. Try to make the triangles not be congruent to each other. Use the rulers to measure the sides of the triangles. Does having one leg in one right triangle congruent to a leg in another right triangle guarantee that the triangles are congruent?

Under 'Condition', select 'Both legs congruent'. Drag the vertices of the triangles to form new right triangles. Try making the triangles not congruent. Use the protractors to measure the angles and the rulers to measure the hypotenuses.

Congruent Shapes is an interactive game students can play to practice division skills.

To use Congruent Shapes, click on the level of difficulty and then the 'Start' button. Determine if the shapes need to be turned or flipped. Drag the pieces onto the glass window to put them in the correct places before the time runs out. To begin again, click the 'Restart' button.  