Angles in a quadrilateral
Name: _____________________ Date: __________
Show your thinking with numbers, words, or a drawing.
1. Find the missing angle in the quadrilateral, marked with a question mark. The diagram is not drawn to scale.
2. Find the missing angle in the quadrilateral, marked with a question mark. The diagram is not drawn to scale.
3. Find the missing angle in the quadrilateral, marked with a question mark. The diagram is not drawn to scale.
4. Find the missing angle in the quadrilateral, marked with a question mark. The diagram is not drawn to scale.
5. Find the missing angle in the quadrilateral, marked with a question mark. The diagram is not drawn to scale.
Answer key · Angles in a quadrilateral
1. 55
The angles in a quadrilateral add up to 360°.
Add the angles you know: 100 + 115 + 90 = 305.
360 − 305 = 55, so the missing angle is 55°.
2. 125
The angles in a quadrilateral add up to 360°.
Add the angles you know: 70 + 105 + 60 = 235.
360 − 235 = 125, so the missing angle is 125°.
3. 60
The angles in a quadrilateral add up to 360°.
Add the angles you know: 80 + 90 + 130 = 300.
360 − 300 = 60, so the missing angle is 60°.
4. 125
The angles in a quadrilateral add up to 360°.
Add the angles you know: 75 + 65 + 95 = 235.
360 − 235 = 125, so the missing angle is 125°.
5. 50
The angles in a quadrilateral add up to 360°.
Add the angles you know: 130 + 110 + 70 = 310.
360 − 310 = 50, so the missing angle is 50°.
Try it together
Choose a question from the printable. Use objects or a drawing to show your thinking, then explain your method to someone at home.