Since b = c, the angles B and C also equal
so you get
180 - 45 = 135
135/2 = =67.5 for each angle
now we know 2 sides and all 3 angles, use the law of sines to find a
b/sin B = a/sin A
4/(sin 67.5) = a/(sin 45)
a = 4(sin 45)/(sin 67.5)
a^2 = (4(sin 45)/(sin 67.5))^2
a^2 = 9.37
Answer is C
Answer: 20
Step-by-step explanation:
