Missing Angles worksheet - Free Printable

You're given 6 diagrams where two angles lie on a straight line. As the instructions say:

> *Remember, the two angles should add up to 180° because they are in a straight line!*

This is the key concept: angles on a straight line are supplementary, meaning their measures sum to 180°.

We’ll solve each one by subtracting the given angle from 180°.

---

1) Find a°

Given angle = 47°
So,
a = 180 - 47 = 133°

✔ a = 133°

---

2) Find x°

Given angle = 118°
So,
x = 180 - 118 = 62°

✔ x = 62°

---

3) Find n°

Here, both angles are labeled n°, and they form a straight line.
So:
n + n = 180
→ 2n = 180
→ n = 90°

✔ n = 90°

*(This also makes sense — it’s a right angle split into two equal parts by a perpendicular line.)*

---

4) Find y°

Given angle = 134°
So,
y = 180 - 134 = 46°

✔ y = 46°

---

5) Find b°

Given angle = 153°
So,
b = 180 - 153 = 27°

✔ b = 27°

---

6) Find g°

Given angle = 165°
So,
g = 180 - 165 = 15°

✔ g = 15°

---

## ✔ Final Answers:

1) a = 133°
2) x = 62°
3) n = 90°
4) y = 46°
5) b = 27°
6) g = 15°

Let me know if you’d like a visual explanation or more practice!