Solving a)
To solve this problem, we need to remember the following property of triangles:
The sum of the internal angles of any triangle has to be equal to 180°.
In this case for the triangle in a) the sum of the internal angles is:
Where x is the unknown angle. This sum has to be equal to 180:
Now we need to solve for x.
• To solve for x the first step is to combine the like terms on the left side of the equation:
• Subtract 121 to both sides of the equation:
• Solve the subtraction:
Answer:
x = 59°