The Inscribed Angle Theorem states that the measure of an inscribed angle is half the measure of its intercepted arc. Therefore, 112^(∘) is half of the sum of 104^(∘) and b^(∘). We can write and solve an equation to find the value of b.
Once again, by the Arc Addition Postulate we know that the measure of the intercepted arc of the inscribed angle whose measure is 71^(∘) is the sum of 104^(∘) and c^(∘).
By the Inscribed Angle Theorem we know that 71^(∘) is half of (104+c)^(∘).
