Points A, O and D lie on a straight line. Two rays OB and OC are drawn from O between A and D. Angle AOB = (3x + 15)°, angle BOC = 90°, and angle COD = (x + 15)°. Find angle COD.
Show Worked Solution
Worked Solution
Step 1: Angles AOB, BOC and COD lie on straight line AOD, so they sum to 180°.
(3x + 15) + 90 + (x + 15) = 180
Step 2: Collect like terms.
4x + 120 = 180
Step 3: Solve for x.
4x = 180 − 120 = 60
x = 15
Step 4: Find angle COD.
COD = (x + 15)° = 15 + 15 = 30°
Check: (3(15) + 15) + 90 + 30 = 60 + 90 + 30 = 180° ✓
Answer: 30°
Answer: 30°
Correct answer: 30°
Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.
Start Free Trial — 7 Days Free