size(9cm);
// x = 10 => A = 70, B = 40, C = 70 (BA = BC)
pair B = (0, 0);
pair C = (6, 0);
pair A = 6*dir(40);
// D: CBD = 30, BCD = 40
pair D = extension(B, B + dir(30), C, C + dir(140));
draw(A--B--C--cycle, black+1);
draw(A--D);
draw(B--D);
draw(C--D);
markangle("$x$", D, B, A, radius=1.1, black);
markangle("$2x$", B, A, D, radius=0.55, black);
markangle("$5x$", D, A, C, radius=0.85, black);
markangle("$3x$", A, C, D, radius=0.55, black);
markangle("$4x$", D, C, B, radius=0.9, black);
dot("$A$", A, N);
dot("$B$", B, W);
dot("$C$", C, E);
dot("$D$", D, S);