Question

1. what is the measure of angle r, given the largest triangle is a right triangle? 12° 45° 78° 33°

Explanation:

Step1: Identify angles in right triangle

The largest triangle is right-angled, so the sum of its non-right angles is $90^\circ$. The angle opposite the $12^\circ$ arc is equal to $12^\circ$ (inscribed angles subtended by equal arcs are equal). Let angle R be $x$.

Step2: Calculate angle R

The two non-right angles are $12^\circ$ and $x$, so $12^\circ + x = 90^\circ$. Solve for $x$: $x = 90^\circ - 12^\circ = 78^\circ$.

Answer:

78°