9.7/9.8 Angles Inside and Outside the Circle HW: 9.7 ALL 9.8 ALL

Essential Question: How do the areas and perimeters of similar shapes compare?

Talk with your neighbor… What angle did you learn yesterday that is on a circle? What do you know about it?

∠ formed by a chord and tangent is ½ the measure of the intercepted arc

intersect inside ½ the sum

Circle Formulas/Thms Packet Take 3min to write these thms in your packet in your own words. Write it so you will understand it. Add a picture too! Chord/Tangent Angle Thm Intersecting Chords Angles Thm

124/2= 62°

50 + a + 45 = 180 a = 85° 45 x 2 = 90 b = 45° 50 x 2 =100 c =50°

Now you try! 133 x 2 = 266°

(129+71)/2= 200/2= 100°

Technology Break 5 min HW: 9.7 ALL 9.8 ALL

Essential Question: How do you find the measure of an angle outside of a circle?

Circle Formulas/Thms Packet Take 3min to write these thms in your packet in your own words. Write it so you will understand it. Add a picture too! External Angles Thms # 1, 2, and 3

7222

12032 Try on your own!

– 141 – 187= 32

Plicker Exit Quiz Question 1 Question 2 Solve for a. A) 30° B) 60° C) 90° D) 120° Solve for b. A) 30° B) 60° C)90° D) 120°

9.7 ALL 9.8 ALL

9.10/9.11 Segments from Secants and Tangents HW: 9.10 (1, 2, 4, 5, 7, 9, 12, 13) 9.11 (1, 6, 8, 9, 11, 12, 15)

Essential Question: How can you find the length of intersecting secants?

18 (x +18) = 640 x + 18 ≈ 35.6 x ≈ 17.6 __ (____) = __ (__) 18x x

2x 2 = 288 x 2 = 144 x = 12 __ (____) = __ (__) x2x932 2x

False Draw a counterexample

Technology Break 5 min HW: 9.10 (1, 2, 4, 5, 7, 9, 12, 13) 9.11 (1, 6, 8, 9, 11, 12, 15)

Essential Question: How can you find the lengths of intersecting secants and tangents?

x 2 = 64 x = 8 __ (____) = __ (__) xx416 x 16

x 2 = 36 x = 6 4 Try this one yourself! x 2

400 = 30y + y 2 0 = y 2 +30y – = (y +40)(y – 10) y = 10 __ (____) = __ (_____) 2020y 30 + y 30+y

9.10 (1, 2, 4, 5, 7, 9, 12, 13) 9.11 (1, 6, 8, 9, 11, 12, 15) Test Next Wednesday!

9.9 Segments from Chords and 9.12 Circles in the Coordinate Plane HW: 9.9 ALL 9.12 Odds

Essential Question: How can you find the lengths of intersecting chords?

When 2 chords intersect the products of their segments are equal a x b = c x d

a x b = c x d 12 x 8 = 10 x x 96= 10x 9.6 = x 9 x 5 = 15 x x 45 = 15x 3 = x You try!

a x b = c x d 8 x 24 = 12 (3x + 1) 192 = 36x = 36x 24(x – 9) = 21(x – 5) 24x = 21x – 105 3x = 111 You try! 5 = x x = 37

a x b = c x d 4.25 x 4.25 = 1.75x = 1.75x cm = x

5min Break Put the intersecting chords thm in your packet. HW 9.9 ALL 9.12 Odds

Essential Question: How do you graph a circle in the coordinate plane?

(h, k) = (0, 0) r = 3

(-3, 9) (-3, -3) (-3, 3) r=6 6 2 = (x – (-3)) 2 + (y – 3) 2 36 = (x + 3) 2 + (y – 3) 2

(8 + 1) 2 + (-3 – 5) 2 = 50 (9) 2 + (–8) 2 = = 50 NO (-2 + 1) 2 + (2 – 5) 2 = 50 (-1) 2 + (–3) 2 = = 50 NO

9.9 ALL 9.12 Odds