1. Day 2 of Circles
11-1 Tangent Lines

2. Unit 8 Warm-Up # 1
What algebraic formulas would you use to verify that quadrilateral ABCD with vertices A(–5, –1), B(–9, 6), C(–1, 5), and D(3, –2) is a rhombus.
An isosceles trapezoid TRAP has a perimeter of 46 and median length of 15, find the lengths of the legs.
Triangle GHI will be dilated by a scale factor of 3, resulting in Triangle G’H’I’ . What rule describes this transformation?

3. What is a circle?
A circle is a set of all points in a plane equidistant from a given point, the center.
Radius: segment with one
Endpoint at the center and the
Other endpoint on the circle
**All radii of a circle are congruent**

4. Name: A

5. When a line is tangent to a circle
it means that the line intersects
the circle at exactly one point.
The point where a circle and a tangent line intersect is the called the point of tangency.
BA is a tangent segment
B is the point of tangency.

6. Theorem
A tangent line and a radius of a circle are perpendicular at the point of tangency.

7. Theorem
Two segments tangent to a circle from the same point outside the circle are congruent.

8. Inscribed vs. Circumscribed
The Triangle is CIRCUMSCRIBED about the circle: The triangle is INSCRIBED in the circle

9. Ex 1.

10. Ex,2

11. Ex 3:

12. Ex 4:

13. Ex 5
Hint: Create a Rectangle!

14. Ex. 6 Find the distance between the two pulleys

15. Ex 7: find the Perimeter of ABC.

16. Complete the worksheet