When enlarging a shape through a centre (O in this case, which is the usual letter of the origin for x/y axes) measure the distance from each point on the shape to the centre of enlargement, multiply it by the scale factor to get the new distance and then (keeping the measuring device, eg ruler, still) measure the new distance from the centre.
By having a scale factor the exact size of the image is known; and
by having a centre of enlargement the exact position of the image is known.
Note: When the scale factor is negative, the distances will change sign and so be measured in the opposite direction.
So in this case, the following will happen:
. . . . . . . . . . . . . . . . . . . . . .
. . . ./\ . . . . . . . . . . . . . . . . .
. . . / .\. . . . . . . . . . . . . . . . .
. . ./__\ . . . . . .O . . . \ . . ./. .
. . / . . .\. . . . . . .* . . . \--/. .
. ./. . . . \ . . . . . . . . . . .\/ . . .
. / . . . . .\. . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
Where the A shape on the left becomes the (smaller) upside down A on the right when enlarged with a scale factor of -½ and centre O.
(You'll have to excuse the ASCII graphics for not complete accuracy.)
Scaling will proportionally reduce or enlarge a figure. The amount of scaling is given by the scale factor (greater than zero) If the scale factor is less than 1, the figure is reduced and it is sometimes called a contraction If the scale factor is greater than 1, the figure is enlarged, and it is called a dilation or enlargement. If a centre of enlargement is used, the distance of every point from the centre is multiplied by the scale factor. The scale factor can be negative in which case the distance to the new point is measured on the opposite side of the centre to the original point.
No, there cannot be a zero in any scale factor.
To enlarge a figure on a coordinate graph, you can apply a dilation transformation using a scale factor. Choose a center point for the dilation, often the origin or the center of the figure, and multiply the coordinates of each vertex by the scale factor. For example, if you use a scale factor of 2, each coordinate (x, y) becomes (2x, 2y), effectively doubling the size of the figure while maintaining its shape and proportions.
Scaling changes the size of a figure. If the scale factor is greater than 1, the figure is enlarged; if the scale factor is less than 1, the figure is reduced. I the scale factor is equal to 1, the figure's size is unchanged. If there is a centre of enlargement, the new figure can be drawn exactly by multiplying the distance of every point from the centre of enlargement, multiplying this by the scale factor and drawing the new point at this distance from the centre of enlargement. (For a polygonal figure, only the vertices need be measured and the lines between the vertices of the original figure drawn in). With a centre of enlargement, the scale factor can be negative. In this case, the distance to the new points is measured on the opposite side of the centre to the original points, so that it is a straight line form the original point, through the centre to the new point.
None. The vertices, the scale factor as well as the centre of dilation can each be defined independently of the other two. Each different combination will result in a different image.
The way you use a scale factor to enlarge a triangle is to multiply each side of the triangle by that scale factor. Your triangle will then be that many times larger.
Scaling will proportionally reduce or enlarge a figure. The amount of scaling is given by the scale factor (greater than zero) If the scale factor is less than 1, the figure is reduced and it is sometimes called a contraction If the scale factor is greater than 1, the figure is enlarged, and it is called a dilation or enlargement. If a centre of enlargement is used, the distance of every point from the centre is multiplied by the scale factor. The scale factor can be negative in which case the distance to the new point is measured on the opposite side of the centre to the original point.
times by two
It depends where the centre of enlargement (dilation) was; it can be any value.As all you have given us is the change in the coordinate of the A vertex, so all we can conclude is that the centre of enlargement is somewhere along the line y + 2x = 0.Examples:If the centre is at (3, -6) then the scale factor is -6If the centre is at (0.5, -1) then the scale factor is -1If the centre is at (0, 0) then the scale factor is -3/4If the centre is at (-3, 6) then the scale factor is 0If the centre is at (-4, 8) then the scale factor is 1/8If the centre is at (-10, 20) then the scale factor is 1/2If the centre is at (11, -22) then the scale factor is 2If the centre is at (1.4, -2.8) then the scale factor is 6(As the centre tends towards ±∞ the scale factor tends towards 1 [from below towards -∞, from above towards +∞].)
Scale Factor
a scale factor of 4.5 is your answer
A negative scale factor is used to produce the image on the other side of the centre of enlargement (scaled to the absolute value of the scale factor).
No, there cannot be a zero in any scale factor.
No a scale factor of 1 is not a dilation because, in a dilation it must remain the same shape, which it would, but the size must either enlarge or shrink.
Scale factor can enlarge or decrease SIDE lengths, however, angle measurements will not change. Scaling creates similar figures.
When a shape is enlarged, the scale factor tells by how much to multiply each length of the original shape to get the corresponding length on the new shape. So with a scale factor for 0.5 (or 1/2), each length of the new shape is 0.5 (or 1/2) times the lengths of the original shape. For example, to enlarge a triangle with sides 6", 8", 10" by a scale factor or 0.5, the lengths become 6" x 0.5 = 3", 8" x 0.5 = 4", 10" x 0.5 = 5"; so the resulting triangle has sides 3", 4", 5". To do the enlargement through a centre of enlargement, a straight line is drawn from each point (vertex) of the shape to the centre of enlargement. The distance from the centre to the point is measured and multiplied by the scale factor; this new distance is measured along the same line from the centre of enlargement as the original point. In this case, negative scale factors can be given, in which case the new distance is measured in the opposite direction from the centre of enlargement, away from the original point.
When doing enlargements through a centre, the new position of any point is the distance of that point from the centre multiplied by the scale factor; it is easiest to treat the x- and y- coordinates separately.To enlarge (2, 4) by a scale factor of ½ with (4, 6) as the centre of enlargement:x: distance is (4 - 2) = 2 → new distance is 2 × ½ = 1 → new x is 2 + 1 = 3y: distance is (6 - 4) = 2 → new distance is 2 × ½ = 1 → new y is 4 + 1 = 5→ (2, 4) when enlarged by a scale factor of ½ with a centre of (4, 6) transforms to (3, 5).