For irrational numbers written in decimal form, the following statements are true:
A. Irrational numbers are nonterminating. - This statement is true because irrational numbers cannot be expressed as a finite decimal.
C. Irrational numbers are nonrepeating. - This statement is also true because the decimal expansion of irrational numbers does not exhibit any repeating pattern.
The other statements are false:
B. Irrational numbers are repeating. - This statement is false because irrational numbers do not have a repeating pattern in their decimal form.
D. Irrational numbers are terminating. - This statement is false because irrational numbers cannot be expressed as a terminating decimal.
In summary, the true statements regarding irrational numbers written in decimal form are A and C.