# Functional Skills: Angles in 2D Shapes

## Functional Skills: Angles in 2D Shapes Revision

**Angles in 2D Shapes**

Here, we will look at how to find missing **angles in 2D shapes**, using certain rules that always apply.

There are **2** rules that you need to learn.

**Rule 1: Angles in a Triangle add up to 180\degree**

If you add up each angle in a triangle, the answer will always be 180\degree.

\textcolor{red}{A + B + C = 180 \degree}

You can then use this rule to find the missing angles in triangles.

You may also need to use other triangle properties, such as angles in an equilateral triangle all being the same size, or two angles in an isosceles triangle being equal.

**Rule 2: Angles in a Quadrilateral add up to 360\degree**

If you add up each angle in a quadrilateral, the answer will always be 360\degree.

\textcolor{blue}{A + B + C + D = 360 \degree}

You can then use this rule to find the missing angles in quadrilaterals.

You may also need to use other quadrilateral properties, such as lines of symmetry and equal angles.

## Follow Our Socials

Our Facebook page can put you in touch with other students of your course for revision and community support. Alternatively, you can find us on Instagram or TikTok where we're always sharing revision tips for all our courses.

**Example 1: Finding Missing Angles in Triangles**

The diagram is an isosceles triangle. Find the missing angles in this isosceles triangle.

**[2 marks]**

All three angles add up to 180\degree.

So, the missing angles add up to

180 \degree - 70 \degree = 110 \degree

An isosceles triangle has two equal angles, so the missing angles are both

110 \degree \div 2 = 55 \degree

**Example 2: Finding Missing Angles in Triangles**

The diagram is a right-angled triangle. Find the value of angle x.

**[1 mark]**

All three angles add up to 180\degree.

The triangle is a right-angled triangle, so one of the angles is 90 \degree.

So, the missing angle, x, is

x = 180 \degree - 90 \degree - 50 \degree = 40 \degree

**Example 3: Finding Missing Angles in Quadrilaterals**

The diagram shows a quadrilateral. Find the value of angle A.

**[1 mark]**

All four angles add up to 360\degree.

One of the angles is 90 \degree, since it is a right-angle.

So, the missing angle, A, is

A = 360 \degree - 120 \degree - 90 \degree - 80 \degree = 70 \degree

**Example 4: Finding Missing Angles in Quadrilaterals**

The diagram shows a quadrilateral, with two lines of symmetry. Find the values of angles A, B and C.

**[2 marks]**

There are two lines of symmetry, so

- angle A = 150 \degree
- angle B = angle C

So, the sum of angles B and C is

360\degree - 150\degree - 150\degree = 60\degree

Therefore, angle B and C are both

60\degree \div 2 = 30 \degree

## Functional Skills: Angles in 2D Shapes Example Questions

**Question 1:** The diagram below shows a triangle.

Find the missing angle labelled A.

**[1 mark]**

Angles in a triangle add up to 180\degree, so

A = 180 - 75 - 45 = 60\degree

**Question 2:** What is the size of each angle in an equilateral triangle?

**[1 mark]**

Angles in a triangle add up to 180\degree, and each angle in an equilateral triangle is equal.

Therefore, each angle is

180 \div 3 = 60\degree

**Question 3:** The diagram below shows a parallelogram. A parallelogram has two pairs of equal angles.

Find the values of angles A, B and C.

**[2 marks]**

Angle A is equal to 70\degree, which is one pair of equal angles.

Therefore, the sum of angles B and C is equal to

360 - 70 - 70 = 220 \degree

So, angles B and C are both

220 \div 2 = 110 \degree

## Functional Skills: Angles in 2D Shapes Worksheet and Example Questions

### Angles in 2D Shapes L2

FS Level 2NewOfficial PFS[responsive-flipbook id=”pfs_pocket_revision_guide_-_sample”]

## Revision Products

### Functional Skills Maths Level 2 Pocket Revision Guide

Revise and practice for your functional skills maths level 2 exam. All topics covered in this compact revision guide.

### Functional Skills Maths Level 2 Mini Tests

Practice for your functional skills Maths level 2, questions from every topic included.

### Functional Skills Maths Level 2 Revision Cards

Revise for functional skills maths level 2 easily and whenever and wherever you need. Covering all the topics, with revision, questions and answers for every topic.

### Functional Skills Maths Level 2 Practice Papers

This 5 set of Functional Skills Maths Level 2 practice papers are a great way to revise for your Functional Skills Maths Level 2 exam. These practice papers have been specially tailored to match the format, structure, and question types used by each of the main exam boards for functional skills Maths. Each of the 5 papers also comes with a comprehensive mark scheme, so you can see how well you did, and identify areas to improve on.

### Functional Skills Maths Level 2 Practice Papers & Revision Cards

This great value bundle enables you to get 5 functional skills maths level 2 practice papers along with the increasingly popular flashcard set that covers the level 2 content in quick fire format.