SAT Math 4.2 Geometry and Measurement

SAT Math 4.2 Geometry and Measurement

Additional Topics in MathRight triangle problems (word problems)
CongruenceExperiment with transformations in the plane
Understand congruence in terms of rigid motion
GeometryExperiment with transformations in the plane
Triangles
Understand congruence in terms of rigid motions
Understand similarity in terms of similarity transformations
Geometry and MeasurementTransformations
LanguageEnglish Language
Product TypeSAT Math
SAT MathGeometry and Measurement
Similarity, Right Triangles, and TrigonometryUnderstand similarity in terms of transformations
TrianglesTypes of Triangles

Transcript

00:27

…maybe it was getting stir crazy and wanted a change of scenery.

00:30

Whatever the reason, this problem tells us that we must first rotate the sucker 90 degrees about the origin…

00:36

…and then reflect it across the y axis.

00:40

When we rotate the triangle about the origin,

00:42

that means that we have to picture the entire thing on a hinge…

00:46

…and that hinge is at zero, zero.

00:48

…we just have to imagine that pivot point, and swing the whole thing around from there.

00:53

When we do that, our triangle ends up here…

00:55

…with point C at (-2, -1).

00:59

And now the easy part. When we reflect a shape across an axis, all we do is flip it.

01:04

We can see that point C now sits at (2, -1)…

01:07

…which is choice E, our final answer.