Brainlag Plus
Brainlag PlusExact answers
Answers in terms of π, surds kept exact, standard form by hand, and powers and roots of numbers you can work out in your head.
Leave π in the answer
"Give your answer in terms of π" means do not multiply by 3.14. The answer 36π is exact; 113.04 is rounded.
- A semicircle with diameter 10 cm
- radius = 5 cm
- area = ½ × π × 5² = 12.5π cm²
- perimeter = ½ × π × 10 + 10 = 5π + 10 cm
The rest of this lesson and its 9 practice questions are in Plus.
Screen 1 of 5, free to read.
- 9 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards