Brainlag PlusUse surds for exact lengths, areas and distances, and for quadratic solutions in the form a ± b√c.
"Give your answer as a surd"
Do not round. In a right-angled triangle with shorter sides 4 cm and 6 cm, the hypotenuse is √(16 + 36) = √52 = 2√13 cm, exactly.
The distance between (1, 2) and (5, 8) is √(4² + 6²) = √52 = 2√13 in the same way.
The rest of this lesson and its 7 practice questions are in Plus.
Screen 1 of 3, free to read.
- 7 exam-style questions, marked as you go, each with a worked solution
- The Equation Solver beside every question
- Anything you get wrong is saved to your flashcards