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Please help (geometry)

Please help (geometry)-example-1
User Antohoho
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1 Answer

5 votes

Answer: 54 degrees (third choice)

Step-by-step explanation:

AB is a diameter of circle C. This leads to angle ACB being 180 degrees. By Thales Theorem (a special case of the inscribed angle theorem) we know that angle D is 90 degrees.

Therefore, triangle ADB is a right triangle. The acute angles (A and B) add to 90, and we can say they are complementary angles.

A+B = 90

36+B = 90

B = 90-36

B = 54 degrees

User Khatchad
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3.7k points