Answer: ∠TRa = 30°, ∠aRA = 90°, ∠TRA = 120°
Explanation:
I'm not sure if you need the angle of the left triangle only (= 30°)
or if you need the the triangle plus the rectangle (= 120°)
Left Triangle (∠TRa)
The hypotenuse is twice the base so it is a 30° - 60° - 90° triangle
where the base corresponds to the 30° angle.
Rectangle (∠aRA)
A rectangle has four right angles --> four 90° angles.
Angle Sum Theorem
∠TRA = ∠TRa + ∠aRA
= 30° + 90°
= 120°