Answer:
C)3.4 mm
Explanation:
We are given that
Length of side of a triangle,a =4 mm
Length of side of a triangle, b=4 mm
The angle between two sides=
![50^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lwasxee7w4ydip22om1e6mb0b5hpyg8t4s.png)
We have to find the length of third side of triangle.
Cosine law:
![c=√(a^2+b^2-2abcos\alpha)](https://img.qammunity.org/2020/formulas/mathematics/college/8v2hmj175qoztgoegg8e2tknfcs98q6zzl.png)
Substitute the values then we get
![c=\sqrt{4^2+4^2-2(4)(4)cos50^(\circ)}](https://img.qammunity.org/2020/formulas/mathematics/college/yvevi1v0irsltdq608vt9708bakxi2i7wa.png)
![c=3.4 mm](https://img.qammunity.org/2020/formulas/mathematics/college/m6x42mm4u39pe4kcgui9hymjn3035xrl2o.png)
Hence, the length of third side of the triangle=3.4 mm
Option C is true.