Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

Angles Formed by Parallel Lines and Transversals

Holt Geometry

MODULE 3-1 NOTESMODULE 3-1 NOTES

ANGLES FORMED BY PARALLEL LINES & TRANSVERSALSANGLES FORMED BY PARALLEL LINES & TRANSVERSALS

MONDAY AUGUST 26MONDAY AUGUST 26THTH

Holt McDougal Geometry

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

WARM UP

1) IF 2 ANGLES ADD UP TO 900, THEN THEY ARE COMPLEMENTARY

CONVERSE

INVERSE

CONTRAPOSITIVE

2) WHAT VALUE OF Y MAKES THE 2 FIGURES SIMILAR?

IF 2 ANGLES ARE COMPLEMENTARY, THEN THEY ADD UP TO 900

IF 2 ANGLES DON’T ADD UP TO 900, THEN THEY AREN’T COMPLEMENTARY

IF 2 ANGLES AREN’T COMPLEMENTARY, THEN THEY DON’T ADD UP TO 900

8.4

4.8 14.4

y

25.2y

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

TRANSVERSAL – A LINE THAT INTERSECTS 2 COPLANAR LINES AT 2 DIFFERENT POINTS

PARALLEL LINES – LINES IN THE SAME PLANE THAT DO NOT INTERSECT

VOCABULARY

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

FIND EACH ANGLE MEASURE.

EXAMPLE 1: USING THE CORRESPONDING ANGLES POSTULATE

A. mECF

B. mDCE

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

TRY THIS ON YOUR OWN…

Find mQRS.

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

ALTERNATE INTERIOR ANGLES

ALTERNATE EXTERIOR ANGLES

SAME-SIDE INTERIOR ANGLES

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

FIND EACH ANGLE MEASURE.

EXAMPLE 2: FINDING ANGLE MEASURES

A. mEDG

B. mBDG

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

TRY THIS ON YOUR OWN…

Find mABD.

2 10 3 15x x 2 25 3x x 25 x

060m ABD

Alt. Interior Angles

Holt McDougal Geometry

Angles Formed by Parallel Lines and Transversals

CLASSWORKCLASSWORK

m JKL = 1270 m BEF = 630

m 1 = 900 m CBY = 660