Question

The sketch measures 4 in. × 5 in. The scale factor from the sketch to the finished poster was 2 in. to 5 in.

What were the dimensions of the poster?

Answer 1

`\bf \begin{array}{ccllll} sketch&poster\\ \textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\ 2&5\\ 4&w \end{array}\implies \cfrac{2}{4}=\cfrac{5}{w}\implies w=\cfrac{20}{2}\impliedby width`


`\bf \begin{array}{ccllll} sketch&poster\\ \textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\ 2&5\\ 5&l \end{array}\implies \cfrac{2}{5}=\cfrac{5}{l}\implies l=\cfrac{25}{2}\impliedby length`