In the figure below, AD = CD = BC, and angle
C = 2(angle
A). Prove that x = 120° - angle
A. See also Problem 42.
Try to use elementary geometry (Euclid's Elements.)

See
also: Art 00
PicSketch - Pencil Sketch & Drawing Photo Filter Effects
PicSketch by Softease Tech Co., Limited is a photo sketch app
for
iPhone and iPad, to turn photo into
a pencil sketch artwork in a few taps.
|