$(iii)$ Abbreviation used for cosecant of angle $A$ is cosec $A$. And $\cos A$ is the abbreviation used for cosine of angle $A$

Hence, the given statement is false.

$(iv)$ cot $A$ is not the product of cot and $A$. It is the cotangent of $\angle A$.

Hence, the given statement is false.

$(v)$ $\sin \theta=\frac{4}{3}$

We know that in a right-angled triangle,

$\sin \theta=\frac{\text { Side opposite to } \angle \theta}{\text { Hypotenuse }}$

In a right-angled triangle, hypotenuse is always greater than the remaining two sides. Therefore, such value of $\sin \theta$ is not possible.

Hence, the given statement is false