check the picture below
and isosceles triangle, has two equal sides, thus, sides "a" and "b" for the triangle to be an isosceles, have to be equal
5 cups & 4 teaspoons
? cups & 6 teaspoons
2.5 cups is half of 5
2 is half of 4
you increased the recipe by 1/2
so for 6 teaspoons you will need 7.5 or 7 1/2 cups of flour b/c 5 + 2.5 = 7.5
ANSWER: 7 1/2