Centres of a Triangle + Transformation

The centroid is the centre of the three _____________.  

• altitudes

• medians

• angle bisectors

• perpendicular bisectors

Which centres can possibly be outside the triangle?

• Incentre

• Circumcentre

• Centroid

• Orthocentre

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

• The orthocentre is at A.

• The orthocentre is the mid-point of AC.

• The orthocentre is at B.

• The orthocentre is outside ΔABC. .

• A

• B

• C

• D

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

• AG = BG = CG

• AG : GM = 2 : 1

• AG ⊥ BC

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

• It is an equilateral triangle.

• It is a right-angled triangle.

• It is an obtuse-angled triangle.

• It is not possible to have them coincide.