Acute, right and obtuse angles, and measuring in degrees.
Angles and Lines teaches fourth graders to classify angles, add and subtract angle measures, and recognize parallel and perpendicular lines and lines of symmetry. A visual grade 4 geometry course with clear drawings and voice.
Math course · Grade 4
Angles and Lines · Learning goals
Classify angles, add and subtract angle measures, and learn about parallel and perpendicular lines and lines of symmetry.
Why it matters
Acute, obtuse, right, parallel and perpendicular are words kids use in math, art and design.
Clock hands, ramps, roofs and road crossings all have angles. Kids learn to see and measure them.
Lines of symmetry connect math to art, nature and architecture.
Inside Angles and Lines
A short read-aloud lesson first, then hands-on games and a quiz to lock it in.
Step 1 · Lesson
A short read-aloud lesson in 4 steps, with pictures and worked examples.
Step 2 · Game
Acute, right, obtuse or straight? (8 problems)
Step 3 · Game
Add or subtract the angles. (6 problems)
Step 4 · Game
Answer the geometry questions. (6 problems)
Step 5 · Game
Solve the angle problems. (4 problems)
Lesson preview
This is the real lesson text your child hears, read aloud by a friendly voice.
A right angle is like the corner of a square: exactly 90 degrees.
An acute angle is smaller than a right angle: less than 90 degrees.
An obtuse angle is bigger than a right angle but less than a straight line: between 90 and 180 degrees.
Angles add up! A 30 degree angle and a 60 degree angle together make 90 degrees.
For parents
Learning sticks best when kids use it in real life. Here are simple ideas from this course.
Hunt for angles at home: the corner of a book (right), open scissors (acute) and a reclining chair (obtuse). Find a symmetrical object too.
Practice
Real questions from Angles and Lines. Try them with your child, then tap to see the answer.
Question 1
55
Question 2
right triangle
Question 3
65
The full course has 24 questions with instant feedback, stars and rewards. Create a free account to play them all.
Angles and Lines · Questions from parents
Angles and Lines is a grade 4 math course for kids ages 9–10. That is Year 5 maths in the UK and Year 4 in Australia. It also works well for review in the next grade, or as a challenge for a confident younger learner.
Classify angles, add and subtract angle measures, and learn about parallel and perpendicular lines and lines of symmetry. Along the way they practice: Name the Angle; Angle Math; Lines and Shapes; Degree Stories.
About 10 minutes in total, split into 4 short levels. Most kids finish it over two or three sessions. Progress is saved, so they can stop any time and pick up where they left off.
Angles and Lines is part of SkillBloom Premium, which unlocks every course in every subject. Each subject also has free courses, so your child can try SkillBloom before you decide.
No. Every lesson has a friendly read-aloud voice, questions are read aloud too, and the pictures help kids follow along. Confident readers can turn the voice off.
Yes. SkillBloom is built for homeschooling families. Kids work through lessons, games and quizzes on their own, and the parent dashboard shows what they finished and which skills need more practice. It works on phones, tablets and laptops.
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