tuesday, january 31 st

Tuesday, January 31st • Please get a new warm up and complete• Please take out HW (pictures, cartoon, and

worksheet)

Warm Up1. If two shapes are similar and the given

shape has an area of 12 in . What would ²be the area of the resulting shape if the scale factor is 82. If two shapes are similar and the given

shape has a perimeter of 84 cm. What would be the perimeter of the resulting shape of if the scale factor is 7.5

Corny Joke of the Day What’s harder to catch

the faster you run?

Your breath

What did Selena do wrong?

Find the Missing side length given the two

similar shapes

12

45

15 x

15 4512

45 3 15,12 3 4

x

so

Important

Test #2 Friday

February 3rd

Homework Answers

Rotation SymmetryExtension

Review

• A figure has rotational symmetry if, when it is rotated (turned) less than 360° around a central point, it coincides with itself (Looks exactly the same)

• The central point is called the center of rotation.

• A figure that coincides with itself after a rotation of 180° has rotational symmetry

Determining Rotation Symmetry

Tell how many times each figure will show rotational symmetry within one full rotation.

Draw lines from the centerof the figure out throughidentical places in the figure.

Count the number of linesdrawn.

The figure will show rotational symmetry 4 times within a 360° rotation.

Tell how many times each figure will show rotational symmetry with one full rotation.

Draw lines from the center of the figure out throughidentical places in the figure.Count the number of lines drawn.

The figure will show rotational symmetry 3 times within a 360° rotation.

Tell how many times each figure will show rotational symmetry within one full rotation.

Insert Lesson Title Here

Draw lines from the center of the figure out through identical places in the figure.Count the number of lines drawn.

The figure will show rotational symmetry 4 times within a 360° rotation.

Practice Time

Degree of RotationThe smallest number of degrees

that a figure can be turned and still look identical to itself.

Trace the following figure. Rotate the figure and determine the degree of rotation (what degree does it start looking identical to the original?)

Finding the Degree of Rotation

Can be found by:

360° ÷ # of lines of symmetry

Practice Time

Scale Factor ProjectStep 1:

Complete tasks 1-2 using a ruler Measure in Centimeters, round to the nearest 10th

Scale Factor ProjectStep 2:

Find the SCALE FACTOR: Resulting/GivenUse the SCALE FACTOR to find perimeter and Area for question 4

Scale Factor ProjectStep 3:

Answer questions 6-8

Scale Factor ProjectStep 4:

Paste your comic on the small graph paper

Scale Factor ProjectStep 5:

With a ruler, lightly draw in the grid lines

Scale Factor ProjectStep 6:

Answer question 9. Find the perimeter and area of your original comic

Scale Factor ProjectStep 7:

Draw each square in the enlarged grid box