Answer:
BC - 54 units
Step-by-step explanation:
the sum of the 3 angles in a triangle = 180°
∠C = 180° - (∠A + ∠B) = 180° - (80 + 50)° = 180° - 130° = 50°
Since ∠B = ∠C = 50° then the base angles of the triangle are equal hence the triangle is isosceles with
AB = AC, that is
4x - 4 = 2x + 16 ( subtract 2x from both sides )
2x - 4 = 16 ( add 4 to both sides )
2x = 20 ( divide both sides by 2 )
x = 10
⇒ BC = 5x + 4 = (5 × 10) + 4 = 50 + 4 = 54
