Answer:
Solve through trigonmetry:
Im writing the 3 root as 3 because my computer doesnt have the root...though i'll add it in the calculator
For b
Tan-theta= P/B
tan45= 3/b
btan45=3
b=3/tan45
b= 1.73
For a
Sin-theta= P/H
sin45= 3/a
asin45=3
a= 3/sin45
a= 2.45