Question

Not sure how to answer question 4

Answer 1

D = 86
Because its the nearest degree to 90 as you see < BAC seems to be 90

Answer 2

Option D is correct

Explanation:

Applying the cosine theorem for triangle ABC, you would have:

cos (angle BAC) = (BA^2 + CA^2 - BC^2)/(2*BA*CA)

= (10^2 + 18^2 - 20^2)/(2*10*18)

= 24/360

=> angle BAC = ~86 deg

Hope this helps!