Step-by-step explanation:
m<C = 90°
According to the laws of cosine,
c²= a²+b²-2ab. cos(C)
c²=a²+b²-2ab.cos(90°)
c²=a²+b²-2ab.0 { cos(90°)= 0}
c²=a²+b²
a²=c²-b²
[tex]a = \sqrt{ {c}^{2} - {b}^{2} } [/tex]
