PARALLEL LINES CUT BY A TRANSVERSAL DEFINITIONS PARALLEL

PARALLEL LINES CUT BY A TRANSVERSAL

DEFINITIONS • • PARALLEL TRANSVERSAL ANGLE VERTICAL ANGLE CORRESPONDING ANGLE ALTERNATE INTERIOR ANGLE ALTERNATE EXTERIOR ANGLE

DEFINITIONS • SUPPLEMENTARY ANGLE • COMPLEMENTARY ANGLE • CONGRUENT

Parallel lines cut by a transversal 2 3 7 6 8 5 1 4

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 1 and < 2 are called SUPLEMENTARY ANGLES They form a straight angle measuring 180 degrees.

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 Name other supplementary pairs: < 2 and < 3 and < 4 and < 1 < 5 and < 6 and < 7 and < 8 and < 5

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 1 and < 3 are called VERTICAL ANGLES They are congruent m<1 = m<3

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 2 and < 4 < 6 and < 8 Name other vertical pairs: < 5 and < 7

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 1 and < 5 are called CORRESPONDING ANGLES They are congruent m<1 = m<5 Corresponding angles occupy the same position on the top and bottom parallel lines.

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 2 and < 6 < 3 and < 7 Name other corresponding pairs: < 4 and < 8

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 4 and < 6 are called ALTERNATE INTERIOR ANGLES They are congruent m<4 = m<6 Alternate Interior on on the inside of the two parallel lines and on opposite sides of the transversal.

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 Name other alternate interior pairs: < 3 and < 5

Parallel lines cut by a transversal 2 3 7 6 8 1 4 5 < 2 and < 8 Name other alternate exterior pairs: < 1 and < 7

TRY IT OUT 2 3 7 The m < 1 is 6 8 4 5 60 degrees. What is the m<2 ? 1 120 degrees

TRY IT OUT 2 3 7 The m < 1 is 6 8 4 5 60 degrees. What is the m<5 ? 1 60 degrees

TRY IT OUT 2 3 7 The m < 1 is 6 8 4 5 60 degrees. What is the m<3 ? 1 60 degrees

TRY IT OUT 120 60 60 120

TRY IT OUT 2 x + 20 What do you know about the angles? Write the equation. Solve for x. x + 10 SUPPLEMENTARY 2 x + 20 + x + 10 = 180 3 x + 30 = 180 3 x = 150 x = 30

TRY IT OUT 3 x - 120 2 x - 60 What do you know about the angles? ALTERNATE INTERIOR Write the equation. Solve for x. Subtract 2 x from both sides Add 120 to both sides 3 x - 120 = 2 x - 60 x = 60

WEBSITES FOR PRACTICE Ask Dr. Math: Corresponding /Alternate Angles Project Interactive: Parallel Lines cut by Transversal