# What is the radius of the circle?

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#AB=CD=16#

#BC=DA=8#

##### 2 Answers

Nov 9, 2017

4 squares = 16 units; therefore 1 square = 2 units

There diameter of the circle is 20 squares. There for the radius of the circle is 10 squares

Nov 12, 2017

#### Explanation:

note some of the simplification is omitted and is left for the reader to verify.

consider the upper left hand quadrant

consider the triangle

from the diagram it can be seen that

we have aright angled triangle and so apply Pythagoras' theorem

this simplifies to

factorising

either

this cannot be a solution as seen from the diagram

or