Every shape starts with points, lines, and angles. Drag the slider and watch the angle open up — the wider it opens, the bigger the angle.
Try it: set the slider to exactly 90 — that's a right angle, like the corner of a book.
A point marks an exact position, with no length or width — just a dot. A line segment is a straight path between two points, with a fixed length. A ray starts at one point and goes on forever in one direction, like a beam of light. When two rays meet at a point, they form an angle — measured in degrees (°).
Smaller than a right angle.
Exactly a quarter turn.
Bigger than a right angle, less than straight.
A straight line.
Angles are measured in degrees using a protractor. Line up the base line with one ray, and read where the other ray crosses the scale.
A 40° angle is smaller than a 70° angle — just compare the degree measures directly, the same way you'd compare any two numbers.
A rectangle has sides 8 cm and 5 cm. Perimeter = sum of all sides = 8 + 5 + 8 + 5.
Perimeter = 26 cm
A triangle has sides 6 cm, 7 cm, and 5 cm.
Perimeter = 6 + 7 + 5 = 18 cm
A square has each side 9 cm. Since all 4 sides are equal:
Perimeter = 4 × 9 = 36 cm
Answer 3 out of 4 correctly to complete this quest and unlock Percentage City.
Tap a question to reveal its answer once you've tried it yourself.
Two 20-mark, 30-minute tests. Reveal answers question by question.