Chapter 12.1 Tangent Lines

Vocabulary

• Tangent to a circle = a line in the plane of the circle that intersects the circle in exactly one point

Vocabulary

Point of Tangency = point where a circle and a tangent intersect

Vocabulary

• Inscribed in = circle is inscribed in a triangle

• Circumscribed about = triangle is circumscribed about the circle

Theorem 12-1

• If a line is tangent to a circle, then the line is perpendicular to the radius drawn to the point of tangency

Example #1

117

X

Find X

Theorem 12.2

• If a line in the plane of a circle is perpendicular to a radius at its endpoint on the circle, then the line is tangent to the circle

Example #2

• Find X X

Theorem 12.3

• The two segment tangent to a circle from a point outside the circle are congruent

Example #3

Find the perimeter of the triangle

Example #4

Find Y

Classwork/Homework

• Due Tuesday Pgs 665-667 #2,3,8-10, 13-15, 17-19, 25

• Due Wednesday Pgs 665-667 #1,4-7, 11,12, 20, 23