Edexcel IGCSE Maths Make Deductions and Draw Conclusions

Edexcel IGCSE Maths Make Deductions and Draw Conclusions
Edexcel IGCSE Mathematics A syllabusMathematics A 4MA1Issue 2 (2017)

Practise Edexcel IGCSE Maths deductions by comparing circle radii with the distance between centres and writing a conclusion.

How this is tested

  • Add the radii of two circles and compare the total with the distance between centres.
  • Conclude that circles intersect when the centre distance is less than the sum of the radii.

Question 10(b)

Two circles, C1C_{1} and C2C_{2}, are drawn on a centimetre grid, with a scale of 1 cm for 1 unit on each axis.

The centre of circle C1C_{1} is at the point with coordinates (-1,3) and the radius of C1C_{1} is 13 cm.

The centre of circle C2C_{2} is at the point with coordinates (7,18) and the radius of C2C_{2} is 6 cm.

Explain why circle C1C_{1} intersects circle C2C_{2}