The Triangle and Its Properties - Worksheet

The sum of the measures of the three angles of a triangle is always:

An exterior angle of a triangle is equal to the sum of its two ________ opposite angles.

If two angles of a triangle are 45 degrees and 75 degrees, what is the measure of the third angle? Show your calculation.

A triangle with all three sides of different lengths is called a(n):

In a right-angled triangle, the side opposite the right angle is called the _________.

If the exterior angle of a triangle is 110 degrees and one of its interior opposite angles is 60 degrees, what is the measure of the other interior opposite angle?

Define an equilateral triangle.

According to Pythagoras theorem, in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two _________.

Which of the following sets of side lengths can form a right-angled triangle?

A ladder 10 meters long reaches a window 8 meters high from the ground. Find the distance of the foot of the ladder from the base of the wall.