Answer:
m∠BAC=45°
Explanation:
Firs we graph the given points to see the shape of triangle.
We can clearly see that triangle BAC is a right angle triangle whose sides BA and BC both are equal to 4 units.
We know that equal sides of triangle corresponds to equal angles.
Hence
∠A = ∠C ...(i)
We know that sum of all three angles of a triangle is 180°. So we can write
∠A + ∠B + ∠C=180°
∠A + ∠B + ∠A=180° {from (i) }
∠A + 90° + ∠A=180° {∠B is right angle}
2∠A + 90° =180°
2∠A = 90°
divide both siide by 2
∠A = 45°
∠A and ∠BAC are same
Hence
m∠BAC=45°