Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
151 views
in Aptitude by (115k points)
closed by

Points A, B and C lie on the circumference of circle and form ΔABC. BC is the diameter of circle with center O. Find the measure of ∠ACB if ∠ABC = 55°.


1. 35°
2. 60°
3. 70°
4. 65°

1 Answer

0 votes
by (114k points)
selected by
 
Best answer
Correct Answer - Option 1 : 35°

Given:

Points A, B and C lie on the circumference of circle and form ΔABC.

BC is the diameter of circle with center O.

∠ABC = 55°

Concepts used:

Sum of all three angles of triangle is 180°.

According to Thales theorem, the angle formed by the diameter of circle at the point on circle is equal to 90°.

Calculation:

A lies on circumference of circle and lies opposite to diameter BC of circle of centre O.

Applying Thales theorem in ΔABC,

⇒ ∠BAC = 90°

Sum of all three angles of triangle is 180°.

⇒ ∠BAC + ∠ABC + ∠ACB = 180°

⇒ 90° + 55° + ∠ACB = 180°

⇒ ∠ACB = 180° - 145°

⇒ ∠ACB = 35°

∴ Measure of ∠ACB is 35°.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...