the diagram shows a triangle. what is the value of c? c =

Explanation:

Step1: Use the exterior angle theorem

The exterior angle theorem states that an exterior angle of a triangle is equal to the sum of the two non - adjacent interior angles. So, (18c + 7=(17c - 4)+72).

Step2: Simplify the equation

First, expand the right - hand side: (18c + 7=17c-4 + 72). Then, simplify the right - hand side further: (18c + 7=17c + 68).

Step3: Solve for (c)

Subtract (17c) from both sides of the equation: (18c-17c+7=17c-17c + 68), which gives (c+7 = 68). Then subtract (7) from both sides: (c+7-7=68 - 7).

Answer:

(c = 61)