Final answer:
To find m∠STU, we first equate the given angles because ⟡TV bisects ∠STV, then solve for x and use the value of x to calculate the full angle.
Step-by-step explanation:
To solve for m∠STU when ∠STV is bisected by vector ⟡TV, we have that m∠STV = (4/5 × 10)° and m∠UTV = (x - 3)°. Since ⟡TV is the bisector, m∠STV should be equal to m∠UTV.
Therefore, we set up an equation with the given angle measures:
Simplifying the equation gives us:
- 8° = (x - 3)°
- x = 8° + 3°
- x = 11°
Now, to find m∠STU, we add the measures of m∠STV and m∠UTV, which are equal:
- m∠STU = 2 × (4/5 × 10)°
- m∠STU = 2 × 8°
- m∠STU = 16°
Hence, m∠STU is equal to (8/5 × 10)°, which indicates that the correct answer is Option C).