Hi folks!

I'm a bit stuck on this construction question:
Construct the triangle 'pqr' such that: |pq| = 5cm, |qr| = 12cm, |pr| = 13cm.
Prove (i) |

Question

Hi folks!

I'm a bit stuck on this construction question:
Construct the triangle 'pqr' such that: |pq| = 5cm, |qr| = 12cm, |pr| = 13cm.
Prove (i) |<pqr| = 90 degrees.
(ii) the radius of the circumcircle is 6.5cm
(iii) the area of the triangle is 30cm^2
(iv) the radius of the incircle is 2cm.

I've got parts (i), (ii), and (iii) completed, but part (iv) is eluding me. Any thoughts?

anonymous · Answer

What is the center of the circle? :O

anonymous · Answer

The incircle, or the circumcircle?

anonymous · Answer

The circumcircle.

anonymous · Answer

It's halfway along the line |pr|

anonymous · Answer

Is there anything given about the inner circle? I am assuming that it touches all three sides of the triangle.

anonymous · Answer

It does, and we also know that at those points, the radius, and triangle side make a 90 degree angle.

anonymous · Answer

The radius of the $circum$circle is 6.5, but part (iv) asks about the radius of the $in$circle.

experimentx · Answer

sorry .. for that

anonymous · Answer

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