172k views
3 votes
Lines AB and AC tangent to circle k(O) at B and C respectively. Find BC, if m∠OAB=30°, and AB=5 cm.

1 Answer

3 votes

Answer:

5 cm

Explanation:

ΔABC is equilateral, so BC = AB = 5 cm.

____

AO is the perpendicular bisector of BC and the angle bisector of angle A, so ∠OAC = ∠OAB = 30°. Then vertex angle BAC of isosceles triangle ABC is 60°, which means all angles in the triangle are 60° and the triangle is equilateral.

User Bruno Caceiro
by
7.5k points

Related questions

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories