If X is the area of any triangle-PQR and you make a hole in the center of this triangle by first joining the midpoints of each side to create smaller triangle-STU and then again joining the midpoints of triangle-STU to create the hole in the center of this triangle, it would create a donut something like this:

Q
/ \
/ \
/ \
S /_______\ U
/ \ A / \
/ \/_\/ \
/ \ / \
P /_______V_______\ R
T

What is the area of the triangle donut in terms of X?

Triangle PQR has area of X

Triangle STU has area of X/4 because joining midpoints of all 3 sides splits PQR into 4 equal triangles

Triangle A "Hole" also splits STU into 4 equal parts, A has area of X/16

Donut is Triangle PQR-"Hole"

Donut's area is 15X/16