Find the measure of ZBAD if m_BAD = 6x + 10º, mzB=3x - 10° and mzBCA= 5x +
90

∠ BAD = 43°

Step-by-step explanation:

The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.

∠ BAD is an exterior angle of the triangle, thus

∠ B + ∠ BCA = ∠ BAD , substitute values

3x - 10 + 5x + 9 = 6x + 10 , that is

8x - 1 = 6x + 10 ( subtract 6x from both sides )

2x - 1 = 10 ( add 1 to both sides )

2x = 11 ( divide both sides by 2 )

x = 5.5

Thus

∠ BAD = 6x + 10 = 6(5.5) + 10 = 33 + 10 = 43°