#### Answer

$t \le -21 \text{ or } t \ge 21$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
To solve the given inequality, $
|t| \ge 21
,$ use the definition of a greater than (greater than or equal to) absolute value inequality.
$\bf{\text{Solution Details:}}$
Since for any $c\gt0$, $|x|\gt c$ implies $x\gt c \text{ or } x\lt-c$ (which is equivalent to $|x|\ge c$ implies $x\ge c \text{ or } x\le-c$), the inequality above is equivalent to
\begin{array}{l}\require{cancel}
t \ge 21
\\\\\text{OR}\\\\
t \le -21
.\end{array}
Hence, the solution set is $
t \le -21 \text{ or } t \ge 21
.$