MathDB

4

Part of 2013 Austria Beginners' Competition

Problems(1)

rectangle wanted, 4 midpoints, point on altitude

Source: Austria Beginners' Competition 2013 p4

10/3/2021
Let ABCABC be an acute-angled triangle and DD a point on the altitude through CC. Let EE, FF, GG and HH be the midpoints of the segments ADAD, BDBD, BCBC and ACAC. Show that EE, FF, GG, and HH form a rectangle.
(G. Anegg, Innsbruck)
geometryrectangle