Answer:
Below.
Step-by-step explanation:
a. As the circumcentre is (0,0) and one point on the circle is (10,0) the radius is 10.
The circle has equation:
x^2 + y^2 = 10^2
x^2 + y^2 = 100.
b. (-5, k) is a point on the circle, so
(-5)^2 + k^2 = 100
k^2 = 100 - 25 = 75
So k = √75
k = 5√3 or 8.66 to 2 places of decimals.
c. The lengths of the 3 sides of the triangles are 10, 10 and 15.8 so it is isosceles.
