To measure lengths and find perimeters, Year 9 students can use some simple methods:

1. Using a Ruler:

   • A regular metric ruler is great for measuring lengths up to 30 cm. It can measure very precisely, down to 1 mm.
   • For bigger shapes, a measuring tape can help, and it can stretch up to 5 meters.

2. Formulas for Finding Perimeter:

   • For rectangles, the formula is ( P = 2(l + w) ). Here, ( l ) is the length and ( w ) is the width.
   • To find the perimeter of a triangle, use the formula ( P = a + b + c ). In this case, ( a ), ( b ), and ( c ) are the lengths of the triangle's sides.

3. Using Digital Tools:

   • There are apps and websites that can give you exact measurements and help with tricky shapes.

4. Unit Conversion:

   • It’s important to know how to change between different units. For example, remember that there are 100 cm in a meter and 10 mm in a cm.

By using these methods, students will be more accurate with their measurements!