Find circle angle with a tangent line

CONCEPTS

Tips

• Tangent line - touches a figure at exactly one point

• A radius is always perpendicular to the tangent line of a circle

PRACTICE PROBLEMS

Question 1 From point A outside a circle and in the same plane as the circle, 2 rays are drawn tangent to the circle with the points of tangency labeled B & C, respectively. Segment BC is then drawn to form triangle ABC. If ∠ A measures 70°, what is the measure of ∠ ABC?

-- Answer -- 55°

180° - 70° = 110°

110° / 2 = 55°

ACT PRACTICE PROBLEMS

1/1

71h

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