#====================
# Figure 9.7.R.
# The generalized Pythagorean relationship
# for all triangles.
#====================
x=c(0,6)
y=c(0,4)
plot(x,y,type="l",lty=0,xlim=c(0,6),ylim=c(-1,4),axes=FALSE,ann=FALSE)
th=4*pi/18
x0=c(0,4,6)
y0=c(0,4,0)
x1=c(4,6,0)
y1=c(4,0,0)
segments(x0,y0,x1,y1,lwd=2)
x2=4
y2=4
x3=4
y3=0
segments(x2,y2,x3,y3,lty=2,lwd=2)
x4=c(3.7,3.7)
y4=c(0,0.3)
x5=c(3.7,4)
y5=c(0.3,0.3)
segments(x4,y4,x5,y5)
text(2.5,-.25,expression(italic(x-a)),cex=1.5)
text(5,-.25,expression(italic(a)),cex=1.5)
text(5.3,2,expression(italic(y)),cex=1.5)
text(1.7,2,expression(italic(r)),cex=1.5)
text(3.8,1.5,expression(italic(h)),cex=1.5)
text(5.4,.4,expression(phi),cex=1.5)