Centres of a Triangle + Transformation

The centroid is the centre of the three _____________.  

Which centres can possibly be outside the triangle?

If ΔABC is a right-angled triangle where ∠ABC = 90°. Where is the orthocentre of ΔABC?

a, b, c are the 3 sides of a triangle. Let r be the radius of the inscribed circle and let $$s=\frac{a+b+c}{2}$$  . Which of the following gives the area of the triangle?

You can see the graph of y = f(x). Draw the graph of $$y=f\left(-x-3\right)$$  .

G is the centroid of ΔABC. M is the mid-point of BC. Which of the following must be correct?

If the orthocentre and the circumcentre of a triangle coincide, which of the following must be correct?

Draw the graph of $$y=2\left(3-x\right)^2-4$$  .