Answer:
h = 8 units
Step-by-step explanation:
We see similar triangles
AD = 20 - 4 = 16 units
since AC = AD + DC = 16 + 4 = 20
so
16: h = h: 4 where corresponding sides are in proportion.
so ... cross multiply in this proportion and solve for h
64 = h^2
h = 8 units it looks like choice F.)
