Presentation on theme: " Answer the following in complete thought sentences. You can use your notes from the other day. What happens to the side lengths, perimeter and area."— Presentation transcript:
Answer the following in complete thought sentences. You can use your notes from the other day. What happens to the side lengths, perimeter and area of shape that is enlarged by a scale factor of 2? Use at least two complete sentences. Get out a piece of paper to take notes. Open your books to Stretching and Shrinking, page 40.
Open your books to Stretching and Shrinking, Page 40 3 4 7.5 x 1.Determine the length of line JK. 2.What scale factor was used to go from Triangle ABC to Triangle JKL? A B C J K L JK = 10 Scale Factor = 2.5
Sketch and make several copies of each of the following shapes: a right triangle an isosceles triangle a scalene triangle
A. Which of these triangles fit together to make a larger triangle that is similar to the original? Make a sketch to show how the copies fit together. All three triangles are rep-tiles. They can all be fit together to make a larger triangle that is similar to the original.
B. Look at your sketches from Question A. 1. What is the scale factor from each original triangle to each larger triangle? 2. How is the perimeter of the new triangle related to the perimeter of the original? 3. How is the area of the new triangle related to the area of the original?
To divide a triangle into four or small similar triangles: Find the midpoints of each of its sides. Draw a straight line connecting each of the midpoints to form the smaller triangles. Important Vocabulary Midpoint – A point that divides a line segment into two segments of equal length.
Open your books to Stretching and Shrinking, Page 42. Get your sheet of graph paper from last Thursday from your class’ exit slip box. Have out paper and pencil and be ready to work.
For parts (1)-(3), draw a rectangle similar to rectangle A that fits the given description. Find the base and height of each new rectangle. 1.The scale factor from rectangle A to the new rectangle is 2.5. 2.The area of the new rectangle is ¼ the area of rectangle A. 3.The perimeter of the new rectangle is three times the perimeter of rectangle A. The new rectangle is 10 by 20. The new rectangle is 2 by 4. The scale factor is ½. Sketch this rectangle on your paper.
For parts (1)-(2), draw a triangle similar to triangle B that fits the given description. Find the base and height of each new triangle. 1.The area of the new triangle is nine times the area of triangle B. 2. The scale factor from triangle B to the new triangle is ½. What is the scale factor?3 New base: 21 New height: 12 Sketch this triangle on your sheet.