To find the area of the rectangle, we need to multiply the height and the width. The height of the rectangle is given as \( (x + 8) \) and the width is \( (x + 1) \).
The area \( A \) is calculated as follows:
\[ A = \text{Height} \times \text{Width} = (x + 8)(x + 1) \]
Now, we can expand this expression using the distributive property (also known as the FOIL method for binomials):
\[ A = x(x + 1) + 8(x + 1) \]
Calculating each term:
- \( x(x + 1) = x^2 + x \)
- \( 8(x + 1) = 8x + 8 \)
Now, we can combine these results:
\[ A = x^2 + x + 8x + 8 \]
Combining like terms (the \( x \) terms):
\[ A = x^2 + 9x + 8 \]
Now, we have the area expressed as a polynomial in standard form:
\[ \boxed{x^2 + 9x + 8} \]