Answer:
a = 60°
Step-by-step explanation:
From the picture attached,
In the given triangle,
NE and ML are the perpendicular bisectors of two sides of the triangle.
Therefore, m∠MEK = m∠MLK = 90°
Since, sum of interior angles of polygon KLME = 360°
m∠MEK + m∠MLK + m∠EML + m∠EKL = 360°
90° + 90° + 120° + a = 360°
a = 360° - 300°
x ≈ 8.66
Using the sine ratio in the right triangle
sin60° = =
Multiply both sides by 10
10 × sin60° = x, thus
x ≈ 8.66 ( to 2 dec. places )