Three circles with their centres and a triangle ABC. Given that D is the midpoint of BC, prove that quadrilateral ABEF and triangle ECF have both equal perimeter and equal area.
Categories
Ceteris paribus
Tag: perimeter
Categories
Slightly skewed
Two overlapping equilateral triangles with side lengths 1. What is the total red length?
Categories
The green field
A square is divided in two quadrilaterals of given area. What fraction of the square’s perimeter is red?
Categories
The Post-it note
Two unit squares (having side 1) are placed as shown. What is the total perimeter of the two red triangles?