В четырехугольнике ABCD: AB=23,∠BAD=123∘,∠ADB=∠BDC, BD — биссектриса ∠ABC. Найдите, чему равна длина BC.

В четырехугольнике <span><span><span><span><span><span>A</span><span>B</span><span>C</span><span>D</span></span></span></span></span></span>:

<span><span><span><span><span><span>A</span><span>B</span><span>=</span><span>23</span><span>,</span><span>∠</span><span>B</span><span>A</span><span>D</span><span>=</span><span><span><span><span>123</span></span><span><span><span><span>∘</span></span></span></span></span></span><span>,</span><span>∠</span><span>A</span><span>D</span><span>B</span><span>=</span><span>∠</span><span>B</span><span>D</span><span>C</span><span>,</span></span></span></span></span></span>

<span><span><span><span><span><span>B</span><span>D</span></span></span></span></span></span> — биссектриса <span><span><span><span><span><span>∠</span><span>A</span><span>B</span><span>C</span></span></span></span></span></span>. Найдите, чему равна длина <span><span><span><span><span><span>B</span><span>C</span></span></span></span></span></span>.