Find UIWebView height dynamically when inside UITableViewCell

I have a custom UITableViewCell like this

// CustomQuestionCell.h
@interface CustomQuestionCell : UITableViewCell {

    IBOutlet UIWebView *mywebView;

}

-(void) AssignWebView:(NSString *) _text;

// CustomQuestionCell.m
-(void) AssignWebView:(NSString *) _text {

     [mywebView setDelegate:self];
    [mywebView loadHTMLString:_text baseURL:nil];

}

I can successfully use the UITableViewCell in UITableView in file called MainViewController. The delagate of UITableViewCell is CustomQuestionCell. In MainViewController I am calling below code to assign value to UIwebview.

// cellForRowAtIndexPath
//CustomQuestionCel.xib uses the class CustomQuestionCell defined above.

CustomQuestionCell *cell = (CustomQuestionCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier];

if(cell == nil) {

    [[NSBundle mainBundle] loadNibNamed:@"CustomQuestionCellView" owner:self options:nil];
    cell = tblQuestionCell;
}

[cell AssignWebView:[ListOfQuestions objectAtIndex:indexPath.row]];



return cell;

I also have the following delegate code in CustomQuestionCell.m

- (void)webViewDidFinishLoad:(UIWebView *)aWebView {
    CGRect frame = aWebView.frame;
    frame.size.height = 1;
    aWebView.frame = frame;
    CGSize fittingSize = [aWebView sizeThatFits:CGSizeZero];
    frame.size = fittingSize;
    aWebView.frame = frame;

    NSLog(@"webview frame size %f",aWebView.frame.size.height);
    [aWebView setOpaque:NO];
    [aWebView setBackgroundColor:[UIColor colorWithRed:249.0/255 green:243.0/255 blue:236.0/255 alpha:1.0]];

    [activityLoad stopAnimating];
    [mywebView setHidden:NO];
}

My problem is I am not able to set the the height of the cell properly in MainViewController which has tableView which uses the custom cell "CustomQuestionCell". In the function

 - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

in MainViewController how can I set the height of the cell as aWebView.frame.size.height ????