check the picture below.
notice, we can find the area of the pink triangle (garden), since we know its base and height, we can also find the areas of the yellow triangle (lawn), since we also know its base and height.
[tex]\bf \stackrel{\textit{area of the garden}}{\cfrac{1}{2}(40)(70)}\implies 1400~\hfill \stackrel{\textit{area of the lawn}}{\cfrac{1}{2}(100)(70)}\implies 3500 \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \cfrac{\textit{area of the lawn}}{\textit{area of the garden}}\qquad \qquad \cfrac{3500}{1400}\implies \cfrac{5}{2}\implies 2\frac{1}{2}\textit{ times larger}[/tex]
