Answer:
This is an equilateral triangle, which means all the sides are equal.
Hence, all three angles are the same.


Therefore,

The midpoint is (-1/2, 2)
Answer:
12.71in
step explanation:
The Length of an arc given is expressed as;
A = theta/360 * 2πr
10 = 45/360 * 2 * 3.14r
10 = 1/8 * 6.28r
Cross multiply
10 * 8 = 6.28r
80 = 6.28r
r = 80/6.28
r = 12.74in
Hence the radius is 12.71in