Question : An exterior angle of a triangle is 115° and one of the interior opposite angles is 45°. The other two angles are:

Option 1: 65° and 70°

Option 2: 60° and 75°

Option 3: 45° and 90°

Option 4: 50° and 85°

Question : If $\cos (A-B)=\frac{\sqrt{3}}{2}$, and $\cos (A+B)=0$, where $A$ and $B$ are positive acute angles and $A \geq B$, then the measures of $A$ and $B$ are:

Option 1: 80° and 10°

Option 2: 60° and 30°

Option 3: 70° and 20°

Option 4: 50° and 40°

Question : The difference between the largest and the smallest angles of a triangle whose angles are in the ratio of 5 : 3 : 10 is:

Option 1: 20°

Option 2: 30°

Option 3: 50°

Option 4: 70°

Question : Two angles of a triangle are equal and the third angle measures 78°. What is the measure of each of the unknown angles?

Option 1: 50°

Option 2: 51°

Option 3: 49°

Option 4: 52°

Question : If the sum and difference of two angles are 135° and $\frac{\pi}{12}$, respectively, then the value of the angles in degree measure is:

Option 1: 70° and 65°

Option 2: 75° and 60°

Option 3: 45° and 90°

Option 4: 80° and 55°