see the link for the figure
let AB be the height of the wall and CD be the height of boy
with BC as distance between them.
we have AE = AB-BE = 3.64-1.54 = 2.1m
and ED = BC = 2.1m
in triangle AED, we have
tanФ = P/B = 2.1/2.1
tanФ = 1
∴ Ф = 45°
Hence the sun is elevated at an angle of 45 °.