Respuesta :

Answer: The value of x is 40

Step-by-step explanation:

Given triangle SRT,

Angle SRT = 20 and Angle SRT = Angle STR

To find Angle STU:

We know that

The sum of all interior angles of triangle is equal to 180.

Angle SRT + Angle STR + Angle RST =180

Also, Angle SRT = Angle STR =20

20+20+Angle RST=180

Angle RST=140.

Now. The exterior angle of triangle is equal to sum of opposite interior angles of triangle,

Angle STU=4x=Angle RST+Angle SRT

4x=20+140

4x=160

x=40

Therefore, The value of x is 40