hi Becky,
You know area = 1/2 b * h b is base and h is height
now base times 1/4 what the new area is
new area = 1/2( 1/4 b )* h
new area = 1/8 b * h it means new area decreased 1/4 or the area was 4 times of new area
As a result, when base changes this will effect on area
I hope it is useful,
Minoo