1981

Prove the red lines are perpendicular.

1720

The blue isosceles right triangles share a vertex at their right angles. Prove if the red triangles are isosceles right, then they also share a vertex.

1714

The yellow and blue triangles are right isosceles. Prove the red shape is a square.

1699

The yellow shapes are squares. The blue points are the midpoints of the green line segments. Prove the red triangle is right isosceles.

1338

The green triangles are isosceles right. Prove the red triangle is also.

1270

Prove the red angles are congruent. Prove the blue angles are congruent.

1188

Prove the green triangle is isosceles right with area $a^2/2$.

1151

Prove the red points are collinear.

1116

Prove the red lines are perpendicular.

1093

Prove the red triangle is isosceles right.

1082

Prove the red triangle is isosceles right.

1055

The blue and green points are the midpoints of the legs of the yellow isosceles right triangle. Prove the red circle is tangent to its hypotenuse.

1048

Prove the red triangle is $45^\circ$-$45^\circ$-$90^\circ$.

967

The yellow and blue triangles are isosceles right. Prove the red line segments are congruent and perpendicular.

686

Prove the red line segment is double the green line segment.

533

Prove the blue line bisects the red line segment.

359

The blue triangles are isosceles right. Prove the red triangle is also.

161

Prove $a^2+b^2=c^2$.