

Geometry problems (11..20) 




problems 1..10 


problems 21..29 
11.
Calculate angle x.
12.
In the figure below we notice rightangled triangles and their inscribed circles.
Question: what is the area of the rectangle for these inscribed circle diameters?
13.
In the figure below we notice rightangled triangles and their inscribed circles.
Question: what is the area of the rectangle for these inscribed circle diameters?
14.
find angles x, y at point D in above picture.
15.
Calculate x in next picture.
16.
Below is pictured rectangle ABCD with BD perpendicular to CE.
Prove that BE x BA = (BC)^{2}.
17.
In picture below AD = DC
LABC = 45 deg.
Question: find angle x.
18.
Calculate angle x.
19.
Triangle ABC is isosceles and right angled.
Proof that angle x = LDCE = 45 degrees.
20.
Given are:
A 180 degree circle arc with center P and radius c.
Within two other half circles with centers M, N and radius a ,b.
c = a + b.
Within also two small circles with radius r which touch the other circles and line AB.
AB is tangent of the inner circle arcs.
Asked:
Express r in a and b.

