Note: Your teacher will grade your responses to questions 4–8 to ensure you receive proper credit for your answers.

Find the value of x. The diagram is not to scale.

Given: angle upper S upper R upper T congruent to angle upper S upper T upper R, mangleSRT = 20, mangleSTU = 4x

Triangle upper R upper S upper T is shown with upper R in the lower left corner moving clockwise around to the other vertices. Segment upper R upper T is horizontal. Point upper U is drawn to the right of point upper T so that ray upper R upper U is formed and drawn.
(1 point)

We are given that angle RST is congruent to angle STR. This means that angle RST = angle STR.

We are also given that angle SRT = 20.

Since the sum of the angles in a triangle is 180 degrees, we can add up the three angles in triangle STR:

angle STR + angle SRT + angle STU = 180

Since angle SRT and angle STU are congruent and angle STR is 20, we can write:

angle STR + 20 + angle STU = 180

Now we can substitute 4x for angle STU:

20 + 4x = 180

Subtract 20 from both sides of the equation:

4x = 160

Divide both sides by 4:

x = 40

Therefore, the value of x is 40.