Question 175735
<pre><font size = 4 color = "indigo"><b>

All are right angles except the three angles 
inside the triangle in the upper part of the "A":

{{{drawing(400,178,-1,8,-1,3,

line(0,0,0,2),  
line(1,0,1,2),
line(0,1,1,1),
line(2,0,2.5,2),
line(3,0,2.5,2),
line(2.25,1,2.75,1),
line(4,0,4,2),
line(4,0,5,0),
line(6,0,6,2),
line(6,0,7,0) )}}}

Edwin</pre>