Traditional Culture Encyclopedia - Photography major - As shown in the figure, two semicircles with diameters of AB and BC, point C is on AB arc, point D is on AB, and AD:DB=2:3, AB.

As shown in the figure, two semicircles with diameters of AB and BC, point C is on AB arc, point D is on AB, and AD:DB=2:3, AB.

BC^2=DB^2+CD^2

=DB^2+AC^2-AD^2

=DB^2+AB^2-BC^2-AD^2

BC^2=(DB^2+AB^2-AD^2)/2

=(36+ 100- 16)/2

=60

BC=2√ 15