Big Idea
Geometry is about using visual facts and formulas carefully.
Geometry
Use shape facts, angle facts, perimeter, area, and simple diagrams.
Understand it first
Angles
Angles on a straight line add to 180 degrees.
Perimeter
Perimeter is the distance around the outside.
Area
Area is the space inside a 2D shape.
Method Ladder
Use this same ladder every time you meet this topic.
- Draw or mark the diagram clearly.
- Write the fact or formula you need.
- Substitute the numbers carefully.
- Include units for length, area, or angle.
Worked example: Find the area of a rectangle 8 cm by 5 cm
- Use area = length x width.
- Substitute: 8 x 5.
- 8 x 5 = 40.
- Answer: 40 cm squared.
Fix It Lab
Read these before the quiz. They are the traps that lose marks.
- Common mistakeMixing up area and perimeter.
- Common mistakeForgetting squared units for area.
- Common mistakeNot using angle facts such as 180 degrees on a line.
Top-mark challenge
Open challenge
A rectangle has area 48 cm squared and length 8 cm. Find its width.
Write full working and one sentence explaining the method.
10-question unlock quiz
The quiz is now on separate pages. You answer one question, then the next question opens. Finish Question 10 to complete this mission.
Start Question 1