9514 1404 393
Answer:
the angle is 30°
Explanation:
The area of a triangle given two sides and the included angle is ...
A = 1/2ab·sin(C)
5 cm² = 1/2(4 cm)(5 cm)sin(θ)
0.5 = sin(θ) . . . . . . divide by 10 cm²
θ = arcsin(.5) ≈ 30°
_____
Additional comment
An obtuse angle of 150° in that location will give a triangle with the same area.