Warm UpWarm Up

Read A Look Back and A Look Read A Look Back and A Look Ahead…Ahead…

Pg 61 in Geometry BookPg 61 in Geometry Book

Write a short paragraph on your Write a short paragraph on your feelings about geometry so far. feelings about geometry so far. Where do you think your challenges Where do you think your challenges will be?will be?

2.12.1

PerpendicularityPerpendicularity

Perpendicular: lines, rays or segments that intersect at right angles.

Τ

Symbol for perpendicular

Τ

a b

a

b

AD

B

AB BD

X

Y

A B

XY AB

ΤΤ

If <B is a right angle, then AB BC

Τ

C

A

B

Can’t assume unless you have a right angle or given.

Τ

x axis

y axis

-3 -2 -1 1 2 3

321

123

A

C

D

B

Given: AB BC

DC AD

Conclusion: <B = <D~

Τ

Τ

PROVE IT!!!!

Given: KJ KM

<JKO is 4 times <MKO

Find both angles (Draw and label the diagram)

Τ

Given EC ll x axis Point C (7,3)

CT ll y axis Point R (-4, -2)

Find the area of RECT

2.2 Complementary and Supplementary Angles