Geometry
posted by Geometry .
In my book there's a picture of an equalderal triangle. This is given information. Inside the triangle all three altitudes have been drawn to find the center point of gravity. The incircle is drawn. The circumcircle is drawn.
Given that the radius of the incricle is 1, what is
24. the radius of the circumcircle
25. the circumference of each circle
26. the area of each circle

the two circles would be concentric, (have the same centre)
Draw the triangle by joining a vertex of the triangle to the centre of the incircle.
Notice that we now have a 30,60,90 triangle with the side across from the 30ยบ equal to 1.
So the other two sides are √3 and 2, with 2 they hypotenuse.
So the inner circle has a radius of 1 (that was given)
and the outer circle has a radius of 2
You should now be able to do the rest of the question. 
chord and tangent of circle