Let’s solve each quadrilateral one by one. Remember:
the sum of all interior angles in any quadrilateral is always 360°. We’ll use that to find the missing angle(s).
---
Problem 1:
Angles given: 95°, 82°, 127°, and x°
Add the known angles:
95 + 82 = 177
177 + 127 = 304
So, x = 360 - 304 =
56°
✔ Check: 95 + 82 + 127 + 56 = 360 → Correct!
---
Problem 2:
Angles given: 78°, 104°, 78°, and x°
Add them:
78 + 104 = 182
182 + 78 = 260
x = 360 - 260 =
100°
✔ Check: 78 + 104 + 78 + 100 = 360 → Correct!
---
Problem 3:
Angles given: 115°, 65°, 115°, and x°
Add them:
115 + 65 = 180
180 + 115 = 295
x = 360 - 295 =
65°
✔ Check: 115 + 65 + 115 + 65 = 360 → Correct!
---
Problem 4:
Angles given: 90°, 90°, 90°, and x°
That’s three right angles.
90 × 3 = 270
x = 360 - 270 =
90°
✔ This is a rectangle or square — makes sense!
---
Problem 5:
Angles given: 70°, 110°, 70°, and x°
Add them:
70 + 110 = 180
180 + 70 = 250
x = 360 - 250 =
110°
✔ Check: 70 + 110 + 70 + 110 = 360 → Correct!
---
Problem 6:
Angles given: 120°, 60°, 120°, and x°
Add them:
120 + 60 = 180
180 + 120 = 300
x = 360 - 300 =
60°
✔ Check: 120 + 60 + 120 + 60 = 360 → Correct!
---
Problem 7:
Angles given: 100°, 80°, 100°, and x°
Add them:
100 + 80 = 180
180 + 100 = 280
x = 360 - 280 =
80°
✔ Check: 100 + 80 + 100 + 80 = 360 → Correct!
---
Problem 8:
Angles given: 110°, 70°, 110°, and x°
Add them:
110 + 70 = 180
180 + 110 = 290
x = 360 - 290 =
70°
✔ Check: 110 + 70 + 110 + 70 = 360 → Correct!
---
Final Answer:
1. x = 56°
2. x = 100°
3. x = 65°
4. x = 90°
5. x = 110°
6. x = 60°
7. x = 80°
8. x = 70°
Parent Tip: Review the logic above to help your child master the concept of angles in a quadrilateral worksheet.
