2155

Prove the red and blue areas are equal.

2154

The blue hexagon is equiangular. Prove the red and green areas are equal.

2145

Prove the red and blue areas are equal.

2118

The blue shape is a parallelogram. Prove the red triangles have the same area.

2112

Prove the area of the red rectangle is the sum of the area of the blue rectangle and twice the area of the yellow triangle.

2048

Prove the blue and red areas are the same.

2001

The blue point is the orthocenter of the blue triangle, the yellow point is the orthocenter of the yellow triangle, and the green point is the orthocenter of the green triangle. Prove the red triangles have the same area.

1987

The yellow and green shapes are squares. Prove the blue and red triangles have the same area.

1969

A square is inscribed in a circle. Prove the red and blue areas are the same.

1902

A rectangle is partitioned into right triangles. Prove the area of the red square equals the sum of the areas of the blue squares.

1880

Prove the blue and red triangles have the same area.

1878

The yellow lines are the angle bisectors of the triangle. The green lines are the perpendicular bisectors of the yellow line segments. Prove the red and blue triangles have the same area.

1828

The blue points are midpoints. Prove the area of the red quadrilateral is half the difference of the areas of the green and yellow triangles.

1780

Prove the area of the red square equals the sum of the areas of the green and blue squares.

1779

Prove the area of the red rectangle equals the sum of the areas of the blue and green squares.

1762

Given a square. Prove the areas of the blue triangle and red quadrilateral are the same.

1749

The red shape is a trapezoid. Prove the area of two blue squares equals the sum of the areas of the two green squares and the two congruent yellow rectangles. (Trapezoid law)

1748

The red shape is a parallelogram. Prove the area of the four yellow squares and the area of the two blue squares are the same. (Parallelogram law)

1742

The green points are the midpoints of the sides of the red quadrilateral. Prove the area of the four yellow squares and the area of the four blue squares are the same.

1741

Given a parallelogram. Prove the area of the red triangle equals the sum of the areas of the green, yellow, and blue triangles.