The three interior angles of a triangle are in the ratio 3 : 4 : 5. What is the degree measure of the largest interior angle?
Answer and explanation
Correct answer: B. 75 degrees
- Step 1: The interior angles of any triangle sum to 180 degrees. Sum of ratio parts: 3 + 4 + 5 = 12. Step 2. Largest angle = (5 / 12) 180 degrees = 5 15 = 75 degrees. Answer: 75 degrees. Why not the others: 60 degrees is the middle angle (4/12 180); 45 degrees is the smallest angle (3/12 180); 80 degrees violates the ratio.
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