Let’s solve each missing angle step by step. Remember: the sum of all interior angles in any quadrilateral is always
360°.
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Part 1: Find the missing angle value in each quadrilateral
#### b)
Angles given: 50°, and two right angles (90° each).
So we have:
50° + 90° + 90° = 230°
Missing angle x = 360° - 230° =
130°
✔ Check: 50 + 90 + 90 + 130 = 360 → Correct!
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#### c)
Angles given: 43°, 75°, 89°
Add them: 43 + 75 + 89 = 207°
Missing angle x = 360° - 207° =
153°
✔ Check: 43 + 75 + 89 + 153 = 360 → Correct!
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#### d)
This one looks tricky — it’s a “dart” or concave quadrilateral, but the rule still applies: total = 360°.
Angles shown: 23°, 215°, 100°
Wait — 215°? That’s a reflex angle (greater than 180°), which is fine for some quadrilaterals.
Add them: 23 + 215 + 100 = 338°
Missing angle x = 360° - 338° =
22°
✔ Check: 23 + 215 + 100 + 22 = 360 → Correct!
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#### e)
Angles given: 70°, 80°, 45°
Add them: 70 + 80 + 45 = 195°
Missing angle x = 360° - 195° =
165°
✔ Check: 70 + 80 + 45 + 165 = 360 → Correct!
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#### f)
Angles given: 119°, and two right angles (90° each)
Add them: 119 + 90 + 90 = 299°
Missing angle x = 360° - 299° =
61°
✔ Check: 119 + 90 + 90 + 61 = 360 → Correct!
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Final Answer:
b) 130°
c) 153°
d) 22°
e) 165°
f) 61°
Parent Tip: Review the logic above to help your child master the concept of quadrilateral angles worksheet.
