Answer :
[tex]\bf \textit{area of a triangle}\\\\ A=\cfrac{1}{2}bh~~ \begin{cases} b=base\\ h=height\\[-0.5em] \hrulefill\\ b=\stackrel{doubled}{2b} \end{cases}\implies A=\cfrac{1}{2}(2b)(h)\implies \stackrel{\textit{twice as the original area}}{A=bh} \\\\[-0.35em] ~\dotfill[/tex]
[tex]\bf \textit{area of a triangle}\\\\ A=\cfrac{1}{2}bh~~ \begin{cases} b=base\\ h=height\\[-0.5em] \hrulefill\\ h=\stackrel{halved}{\frac{h}{2}} \end{cases}\implies A=\cfrac{1}{2}b\left( \cfrac{h}{2} \right)\implies \stackrel{\textit{half of the original area}}{A=\cfrac{1}{2}bh\left( \cfrac{1}{2} \right)}[/tex]
The area is doubled. If you cut the triangle in half, the area is also cut in half.