Angles in Triangles and Quadrilaterals
The angles in a triangle add up to 180°, and the angles in a quadrilateral add up to 360°. Momo the monkey finds the missing angle in a triangle with angles of 65° and 70° (45°), then you find the missing angle in a quadrilateral. Plus a top tip for isosceles triangles.
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2:05Angles: Types, Straight Lines and Around a Point
Leo the lion shows acute, right, obtuse and reflex angles, then uses the fact that angles on a straight line add up to 180° to find a missing angle. Try angles around a point (360°) yourself and learn to estimate first.
1:50Properties of 2D Shapes: The Quadrilateral Family
Professor Hoot the owl introduces the quadrilateral family: square, rectangle, rhombus, parallelogram, trapezium and kite. Solve a riddle using equal sides, right angles and parallel lines ("four equal sides, no right angles" is a rhombus), then solve one yourself, and learn why a square is a special rectangle.
1:58Area and Perimeter of Rectangles
Bruno the bear builds a fence around his 8 m by 5 m garden (perimeter = 26 m) and fills it with squares of grass (area = 40 m²). Learn the difference between around and inside, then find the perimeter and area of a 7 cm by 4 cm rectangle.