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How do i solve this? never learned the formula

Triangle CDE with vertices C(-2, -2) D(1,-4) E(-3,-4):

a) dilation with scale factor of 4 centered (-1, -3)

b) reflection in the line y = -x

1 Answer

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Dilating triangle CDE (C:-2,-2, D:1,-4, E:-3,-4) by 4 centers at origin creates C':(-8,-8), D':(4,-16), E':(-12,-16). Reflecting across y=-x swaps coords, placing C':(-2,2), D':(-4,1), E':(-3,4).

Part (a): Dilation with scale factor 4 centered at the origin

Identify the scale factor and center: We are given a scale factor of 4 and the center of dilation is the origin (0, 0).

Multiply each coordinate by the scale factor:For each vertex of the original triangle CDE, we need to multiply its x and y coordinates by the scale factor of 4.

For C(-2, -2):

C'x = -2 * 4 = -8

C'y = -2 * 4 = -8

Repeat this process for D(1, -4) and E(-3, -4) to find their scaled coordinates D'(4, -16) and E'(-12, -16).

Plot the new triangle: Using the obtained scaled coordinates, plot the triangle C'D'E' on your graph paper or visualization tool. You'll see that C'D'E' is a magnified version of the original triangle, with all its sides and angles stretched by a factor of 4.

Part (b): Reflection in the line y = -x

Identify the reflection line: We are asked to reflect the triangle CDE in the line y = -x. This line passes through the origin and bisects the first and third quadrants.

Swap the coordinates for each vertex: For each point in the original triangle, we need to swap its x and y coordinates.

For C(-2, -2):

C'x = -2 (unchanged as it already lies on the y-axis)

C'y = 2 (swap with x-coordinate)

Repeat this process for D(1, -4) and E(-3, -4) to find their reflected coordinates D'(-4, 1) and E'(-3, 4).

Plot the reflected triangle: Using the obtained reflected coordinates, plot the triangle C'D'E' on your graph paper or visualization tool. You'll see that C'D'E' is a mirror image of the original triangle across the line y = -x. Each vertex will be on the opposite side of the line compared to its original position.

How do i solve this? never learned the formula Triangle CDE with vertices C(-2, -2) D-example-1
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