+4 Find the area of triangle ABC
[asy]
unitsize (2 cm);
pair A, B, C, D, E, F, H;
A = (0,2);
B = (-1,0);
C = (1,0);
D = (0,0);
E = (B + reflect(A,C)*(B))/2;
F = (C + reflect(A,B)*(C))/2;
H = extension(A,D,B,E);
draw(shift((-0.1,0))*(A--H), gray(0.7), Arrows(6));
draw(shift((-0.1,0))*(D--H), gray(0.7), Arrows(6));
draw(A--B--C--cycle);
draw(A--D);
draw(B--E);
draw(C--F);
draw(rightanglemark(A,D,C,3));
draw(rightanglemark(B,E,A,3));
draw(rightanglemark(C,F,B,3));
add(pathticks(B--D, n = 1, s = 4));
add(pathticks(C--D, n = 1, s = 4));
label("$A$", A, N);
label("$B$", B, SW);
label("$C$", C, SE);
label("$D$", D, S);
label("$E$", E, NE);
label("$F$", F, NW);
label("$H$", H, dir(0));
label("$5$", (A + H)/2 + (-0.1,0), W, red);
label("$3$", (H + D)/2 + (-0.1,0), W, red);
[/asy]
