The triangle has vertices A(0, 0), B(3, 0), C(0, 3). The angle at A is:

  1. 90^circ
  2. 30^circ
  3. 45^circ
  4. 60^circ
Answer

A) 90^circ

The slopes of AB and AC multiply to -1 (or one side is horizontal and the other vertical), so angle A = 90^circ. SLO M-09-B-12 · Knowledge

Mathematics MCQ · More Angle Between Lines MCQs · Practise