📐 Shape Up! Mastering Area & Perimeter in Minutes

Whether you are fencing a garden or shading a diagram in your exam, **area and perimeter** calculations appear everywhere in O-Level Mathematics. Getting these measurements right not only secures easy marks but also builds the foundation for more advanced geometry topics.

Unlocking Areas & Perimeters

Remember these **must-know formulae** and you will breeze through most Core questions:

Rectangle: $A = l\times b$ , $P = 2(l+b)$
Triangle: $A = \frac12 b h$ , $P =$ sum of all three sides
Parallelogram: $A = b h$ , $P = 2(a+b)$
Trapezium: $A = \frac12 (a+b)h$ , $P =$ sum of all four sides
Circle: $A = \pi r^2$ , $C = 2\pi r$

Worked Example: Garden Design Challenge

Problem: A trapezium has parallel sides of lengths 12 cm and 18 cm, non-parallel sides of 7 cm and 9 cm, and a height of 5 cm. Find (a) its area and (b) its perimeter.

Step 1:
$A = \tfrac12 (a + b)h = \tfrac12 (12 + 18) \times 5 = 75\,\text{cm}^2$
Step 2:
$P = 12 + 18 + 7 + 9 = 46\,\text{cm}$

Practice these shapes daily, double-check units, and you will convert textbook theory into **exam confidence**!