check radiobutton checked angular code example
Example: angular radio box already showing checked
<label>This rule is true if:</label>
<label class="form-check-inline">
<input class="form-check-input" type="radio" name="mode" [value]="true" [(ngModel)]="rule.mode">
</label>
<label class="form-check-inline">
<input class="form-check-input" type="radio" name="mode" [value]="false" [(ngModel)]="rule.mode">
</label>