Warm UpPlease draw the diagram. State the given and what you want to prove

Your Turn To Present!• With your Row, you will present

4.3• 20 minutes to read over 4.3• Come up with a plan on how you want to present the material

• PowerPoint•Song/Dance •Poster Paper

•Each group has 5 minutes to present the material•Everyone must present!

• YOU WILL BE GRADED FOR THIS ASSIGNMENT

•Count as class participation grade

•I will be looking for:• Creativity (10 Points)• Content – Theorem and proof (20 Points)• Presentation (10 Points)• All members participating (10 Points)

•MUST HAVE THE NEW THEOREM AND A PROOF FROM YOUR TEXTBOOK IN YOUR PRESENTATION!

•BE CREATIVE…….GOOOOOOOOOOOOOOOO!

4.3 A Right-Angle Theorem

Apply one way of proving that two angles are right angles.

T 23: If two angles are both supplementary and congruent, then they are right angles.

1 2

Given: <1 = <2Prove: <1 and <2 are right angles.

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Proof:

Since <1 and <2 form a straight angle, they are supplementary. Therefore, m<1 and m<2 = 180. Since <1 and <2 are congruent, we can use substitution to get the equation:m<1 + m< 2 = 180 or m<1 = 90Thus, <1 is a right angle and so is <2.

You have graduated!!!!!

You no longer need to write the words statement and reason at the top of each proof from now on!!!!

Just make a T bar.

P

Q RS

Given: Circle PS is the mdpt of QR

Prove: PS QRΤ

Given: ABCD is a rhombusAB = BC = CD = AD

Prove: AC BD Τ

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Hint: Draw and label shape! Use a Detour Proof