Answer:
The value of
is
.
Angle R's measure is
.
Angle S' measure is
.
Angle T's measure is
.
Explanation:
Step 1: Construct expressions for the angles in terms of x
The angle R is said to be five more than twice x, which means that 5 is added to 2x:

The angle S is said to be one more than x, which means that 1 is added to x:

The angle T is said to be sixteen less than seven times x, which means that 16 is subtracted from 7x:

Step 2: Create an equation with all the expressions
Since there are three angles in the shape, it is clearly a triangle.
The sum of angles of a triangle is
.
Which means that the sum of the expressions above, would equal to
:

Step 3: Solve the equation
The equation is:

Upon solving it, we get:

Step 4: Calculate the measure of the angles
With
, substitute and calculate the angle R:

Calculate the angle S:

Calculate the angle T:
