The diameter AC and the chord BD intersecting at the point M are drawn in a circle with center O

The diameter AC and the chord BD intersecting at the point M are drawn in a circle with center O, and BM = DM. BAC angle = 35 degrees. Find the corner BAD

We connect points B and D with the center of the circle O.

ΔОВМ = ΔОDM.

<OMB = <OMD (both adjacent to the OM).

Sum of adjacent angles: <OMB + <OMD = 180 °.

Each of these angles is 90 °.

(It is proved that if the diameter divides the chord in half, then the chord and the diameter are mutually perpendicular).

Two right-angled triangles – AVM and AMB – have a common leg AM. The other two corresponding legs are equal by the condition: BM = MD.

Therefore, ΔАВМ = ΔАМB, and <BAM = <MAD = 35 °.

<BAD = <BAM + <MAD = 35 ° + 35 ° = 70 °.

Answer: 70 °.



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