Day 2 of Circles 11-1 Tangent Lines

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?

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**

Name: A

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.

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

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

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

Ex 1.

Ex,2

Ex 3:

Ex 4:

Ex 5 Hint: Create a Rectangle!

Ex. 6 Find the distance between the two pulleys

Ex 7: find the Perimeter of ABC.

Complete the worksheet