2158

Prove the red line segments are congruent.

2157

Prove the blue base angle is double its opposite angle iff the red base angle is double its opposite angle.

2156

Prove the circles are tangent to each other.

2155

Prove the red and blue areas are equal.

2154

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

2153

Given a regular dodecgaon. Prove the red line segments are congruent.

2152

Prove the red point trisects the blue line segment.

2151

The green point is the midpoint of the yellow arc. Prove the red line segment is the sum of the circumradii of the blue circles.

2150

Prove the circles are concurrent.

2149

Prove the red points are concyclic.

2148

Prove the area of the regular dodecagon is $d^2$.

2147

Prove the red angle is $45^\circ$.

2146

Prove the red line bisects the blue arcs.

2145

Prove the red and blue areas are equal.

2144

The green and yellow rectangles are similar. The sides of the yellow rectangle are parallel to the sides of the green rectangle. Prove the red and blue lines are concurrent.

2143

The blue lines are tangent to the circle. Prove the red lines are also.

2142

Prove the red and blue lines are concurrent and the blue lines bisect the red line segment.

2141

Prove the area of the blue quadrilateral is double the area of the red triangle.

2140

Prove the red points are concyclic.

2139

Prove the red triangles are similar.

2138

Prove the red lines are parallel.

2137

Prove the red chords are congruent.

2136

The yellow circles are congruent. Prove the red lines are tangent to the yellow circles.

2135

Prove the red and blue triangles are similar.

2134

The blue shape is a parallelogram. Prove the red circles are tangent to each other.

2133

Prove the red lines are perpendicular.

2132

Prove the red and blue triangles are similar.

2131

Prove the red circles are congruent.

2130

Prove the red angles are congruent.

2129

Prove the red line bisects the blue angle.

2128

Prove the red points are concyclic.

2127

Prove the difference of the green angles equals the difference of the blue angles equals half the difference of the red angles.

2126

The circles are orthogonal. Prove the red points are collinear.

2125

Prove blue and red angles are complementary.

2124

Prove the red line is tangent to the blue circle.

2123

Prove the red lines are parallel.

2122

TBD

2121

Prove the red lines are perpendicular.

2120

The yellow triangle is isosceles. Prove $a^2+b^2=c^2$.

2119

The yellow and blue shapes are parallelograms. Prove the red points are collinear.

2118

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

2117

The green points are the midpoints of the diagonals of the blue quadrilateral. Prove the area of the blue quadrilateral is double the area of the red triangle.

2116

Prove the red lines are concurrent.

2115

The green points are reflected aboutthe midpoints of sides of the yellow triangle. Prove the red line bisects the blue line segment.

2114

The yellow points are the midpoints of the blue and red chords. Prove the red line bisects the green angle.

2113

The blue and green diameters are parallel. Prove the red line segments are congruent.

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.

2111

Given four squares. Prove the red area is double the blue area.

2110

Each base angle is half the angle opposite it. Prove the red angle is $60^\circ$.

2109

Prove the red line segments are congruent.

2108

The blue point is the centroid of the yellow triangle. Prove the red points are collinear.

2107

Prove the red line bisects the blue chord.

2106

Prove the red line segments are congruent.

2105

TBD

2104

The blue point is the orthocenter of the blue triangle. The green point is the orthocenter of the green triangle. Prove the green, red, and blue points are collinear.

2103

The red points are the midpoints of the green chords. Prove the red and blue triangles are similar.

2102

The blue line is a midline of the triangle. The green shape is a rectangle. Prove the red line is the perpendicular bisector of the blue line segment.

2101

The blue points are reflected about sides of the yellow triangle. Prove the red points are concyclic.

2100

The blue angle is double the red angle. The green line is the external angle bisector of the blue angle. Prove $c=\frac{1}{2}(a+b)$.

2099

The blue circles are congruent. The green circles are congruent. The yellow circles are congruent. Prove the red lines are concurrent.

2098

The yellow shape is a parallelogram. Prove one of its sides trisects the red line segment.

2097

Prove the red point is fixed.

2096

Prove the red angles are congruent.