The diagram representation is shown below
From the diagram above, it can be seen that the wall, the ground and the ladder form a right-angle triangle
To find the length x of the ladder needed, we use the Pythagorean theorem
The formula for the Pythagorean theorem is
[tex](\text{Hypotenuse)}^2=(\text{Opposite)}^2+(\text{Adjacent)}^2[/tex]
Where
[tex]\begin{gathered} \text{Hypotenuse}=\text{xft}=\text{Length of the ladder needed} \\ \text{Opposite}=45ft=\text{Height of the house} \\ \text{Adjacent}=28ft=Ground\text{ length} \end{gathered}[/tex]
Substitute values into the Pythagorean theorem formula
[tex]\begin{gathered} (\text{Hypotenuse)}^2=(\text{Opposite)}^2+(\text{Adjacent)}^2 \\ x^2=45^2+28^2=2025+784=2809 \\ x^2=2809 \\ \text{Square root of both sides} \\ \sqrt[]{x^2}=\sqrt[]{2809} \\ x=53ft \end{gathered}[/tex]
Hence, the ladder must be 53ft long