Geometry Honors TNReady Review Practice 4

Front

What is a translation in geometry?

Back

A translation is a transformation that moves every point of a figure the same distance in a specified direction.

Front

How do you find the image of a point after a translation?

Back

To find the image of a point after a translation, you add the translation vector to the original coordinates. For example, for point B(7,-6) translated by (x,y)→(x-5,y+3), the new coordinates are B(7-5, -6+3) = B(2,-3).

Front

What happens to the coordinates of a point when it is reflected across the x-axis?

Back

When a point (x,y) is reflected across the x-axis, its coordinates change to (x,-y).

Front

What is the result of reflecting the point (3,4) across the x-axis?

Back

The result is (3,-4).

Front

How do you determine the angle of rotation needed to map a point on a circle to another point?

Back

To determine the angle of rotation, calculate the difference in positions of the points on the circle and convert that to degrees.

Front

What is the smallest angle of rotation that maps a regular polygon to itself?

Back

The smallest angle of rotation that maps a regular polygon to itself is given by 360° divided by the number of sides. For example, a pentagon has a smallest rotation of 72°.

Front

What is congruence in geometry?

Back

Congruence means that two figures have the same shape and size, and can be made to coincide by rigid transformations such as translations, rotations, and reflections.

Front

What transformation can prove that two triangles are congruent?

Back

Transformations such as translations, rotations, and reflections can prove that two triangles are congruent if one can be mapped onto the other.

Front

What is a reflection in geometry?

Back

A reflection is a transformation that flips a figure over a line, creating a mirror image.

Front

How do you reflect a point across the line y = x?

Back

To reflect a point (x,y) across the line y = x, swap the coordinates to get (y,x).