Answer:
∑ (n = 1 to 5) (2·(-4)^(n - 1))
S5 = 2·((-4)^5 - 1)/((-4) - 1) = 410
Use Law of Cosines g^2 = f^2 + h^2 -2fhCosG f^2 = g^2 + h^2 -2ghCosF h^2 = f^2 + g^2 -2fgCosH
f^2 = 28^2 + 15^2 -2*28*15Cos87 28^2 = 31^2 + 15^2 -2*31*15CosG
f^2 = 784 + 225 - 43.96 784 = 961+225 - 930CosG
f^2 = 965.0378 784 - 1186 = -930CosG
f = 31 -402 = -930CosG Divide by -930
.432258 = CosG
Cos^-1(.432258) = G
G = 64 degrees
Angle H = 180 - 64 - 87 = 29 degrees
Side f = 31 Angle F = 87 degrees
Side g = 28 Angle G = 64 degrees
Side h = 15 Angle H =29 degrees
X = 2.93583423 + πn, 4.9181474 + πn