∠R = 100° , ∠S = 40° and ∠T = 40°
Step-by-step explanation:
In a triangle, sum of all the angles in a triangle is equal to 180 degrees.
In Δ RST,
∠R + ∠S + ∠T = 180°
It is given that,
∠S = ∠T
∠R = 2∠S + 20
So plugin these values in the above equation, we will get,
2∠S + 20 + ∠S+ ∠S = 180
4∠S = 180 - 20
∠S = 160/ 4 = 40
∠R = 2× 40 + 20 = 80 + 20 = 100°
∠S = ∠T = 40°