WHEN TWO POLYGONS ARE ALIKE, THE RATIO OF THE LENGTH OF 2 CORRESPONDING SIDES IT IS CALLED THE- SCALE FACTOR
- EXAMPLE.--The perimeter of the small to the large also grows by the same scale factor.
- If the scale factor from the small to the large is s, then the area of the large figure is squared or to the second power times the area of the small figure.
Perimeter of A = 16
Area of A = 3 x 5 = 15
Perimeter of B = 48
16 x 3 = 48
Area of B = 135
9 x 15 = 135 (15 x 9 = 135)
If the ratio of corresponding sides of the two figures are equal, then the figures are similar
- A = 3/5 = Length/Width
B = 9/15 = 3/5 = Length/Width
- A = 3/5 = Length/Width
test question 1)-(1st picture shown below) Find the scale factor from the larger rectangle to the smaller rectangle, if the two rectangles are similar
Step 1: If we multiply the length of one side of the larger rectangle by the scale factor we get the length of the corresponding side of the smaller rectangle.
Step 2: Dimension of larger rectangle × scale factor = dimension of smaller rectangle
Step 3: 24 × scale factor = 20 [Substitute the values.]
Step 4: Scale factor = 20/24 [Divide each side by 24.]
Step 5: Scale factor = = 5:6 [Simplify.]
test question answer-- 1) 5:6
Step 1: If we multiply the length of one side of the larger rectangle by the scale factor we get the length of the corresponding side of the smaller rectangle.
Step 2: Dimension of larger rectangle × scale factor = dimension of smaller rectangle
Step 3: 24 × scale factor = 20 [Substitute the values.]
Step 4: Scale factor = 20/24 [Divide each side by 24.]
Step 5: Scale factor = = 5:6 [Simplify.]
test question answer-- 1) 5:6
test question 2) - What is the scale factor from triangle CAT to triangle DOG?
step 1) this picture tries to trick you by flipping one of the triangles the opposite way. so if you need to, draw this picture with both triangles facing the same way.
step 2) triangle CAT and triangle DOG are the same triangle except DOG is smaller. By looking at the triangle you can tell that all of the numbers are divisible by 4! so divide them all by 4.
step 3) your answer is 1/4
step 2) triangle CAT and triangle DOG are the same triangle except DOG is smaller. By looking at the triangle you can tell that all of the numbers are divisible by 4! so divide them all by 4.
step 3) your answer is 1/4
answer test question-- 2) 1/4