MathAmigo

Perimeter and Area of Plane Figures

Secondary 1 practice

Start free

Perimeter and Area of Plane Figures practice questions

Secondary 1 topics, the foundation the O-Level Mathematics 4052 syllabus builds on. Every question below has a full worked solution.

When a student gets a question wrong in Math Amigo, it does not show the answer straight away. It reads the working, identifies the step that went wrong, and asks a question that points at the correction. The worked solution is there once a genuine attempt has been made.

Practise Perimeter and Area of Plane Figures free

What this topic covers

Worked examples

Example 1

The area of a triangle is 3636 cm². Its base is 66 cm. Find the height.
Show the worked solution
  • Area=12×b×h\text{Area} = \frac{1}{2} \times b \times h
  • 36=12×6×h36 = \frac{1}{2} \times 6 \times h
  • h=36×26h = \frac{36 \times 2}{6}
  • =726= \frac{72}{6}
  • =12= 12 cm

Answer: 1212

Example 2

Find the area of a circle with diameter 24 cm. Give your answer correct to 1 decimal place.
Show the worked solution
  • r=d2=242=12r = \frac{d}{2} = \frac{24}{2} = 12 cm
  • Area=πr2\text{Area} = \pi r^2
  • =π×122= \pi \times 12^2
  • =π×144= \pi \times 144
  • =452.4= 452.4 cm² (to 1 d.p.)

Answer: 452.4452.4

Example 3

A parallelogram has an area of 72 cm² and a base of 6 cm. Find its height.
6 cmhNot drawn to scale
Show the worked solution
  • Area of parallelogram=b×h\text{Area of parallelogram} = b \times h
  • 72=6×h72 = 6 \times h
  • h=726h = \frac{72}{6}
  • =12= 12 cm

Answer: 1212

Questions parents ask

Is it really free?

The free plan is permanent and does not ask for a card. It has daily limits on the AI feedback, and the paid plans lift them.

Which syllabus does this follow?

O-Level Mathematics (4052), for Singapore secondary students. Math Amigo covers Secondary 1 to 4, both O-Level Mathematics and Additional Mathematics.

Will it just show my child the answer?

No. On a wrong answer it looks at the working, points to the step that went wrong, and asks a question that helps the student find the correction. The full worked solution is available after a genuine attempt.

Other Secondary 1 topics