Can someone me with both these problems? ? thx!

The radius of the circle is 4 cm and the measure of the central angle is 90° the area of the sector with a central angle measuring 90° and radius of length 4 cm is vt cm the triangle in the sector is 4 cm the area of the triangle is v/cm² the area of the segment of the circle is (471 - ) cm?

The solution set for 5v2 – 125 = 0 is

What is the relationship between all triangles that can be drawn given the same three angles