The sum of the interior angles of a triangle is:
Analysis & Theory
The sum of interior angles of any triangle is always 180°.
The sum of the exterior angles of a triangle is:
Analysis & Theory
The sum of the exterior angles, one at each vertex, is always 360°.
In a right-angled triangle, the square of the hypotenuse is equal to:
A
Sum of squares of the other two sides
B
Difference of squares of the other two sides
Analysis & Theory
By Pythagoras theorem: hypotenuse² = base² + perpendicular².
In an equilateral triangle, each angle is:
Analysis & Theory
All angles in an equilateral triangle are equal and each is 60°.
A triangle with all sides unequal is called:
Analysis & Theory
A scalene triangle has all sides unequal and all angles unequal.
A triangle with two equal sides is called:
Analysis & Theory
An isosceles triangle has exactly two equal sides and two equal angles.
The centroid of a triangle is the point where:
B
All altitudes intersect
C
All angle bisectors intersect
D
All perpendicular bisectors intersect
Analysis & Theory
The centroid is the intersection point of the medians of a triangle.
The orthocenter of a triangle is the point where:
A
All altitudes intersect
C
All angle bisectors intersect
D
All perpendicular bisectors intersect
Analysis & Theory
The orthocenter is the intersection point of the altitudes of a triangle.
The circumcenter of a triangle is the point where:
A
All perpendicular bisectors intersect
C
All altitudes intersect
D
All angle bisectors intersect
Analysis & Theory
The circumcenter is the intersection of perpendicular bisectors of the sides and is the center of the circumcircle.
The incenter of a triangle is the point where:
A
All angle bisectors intersect
C
All altitudes intersect
D
All perpendicular bisectors intersect
Analysis & Theory
The incenter is the intersection of angle bisectors and is the center of the incircle.
The medians of a triangle divide it into:
A
Two triangles of equal area
B
Two triangles of unequal area
C
Three triangles of equal area
D
Three triangles of unequal area
Analysis & Theory
All three medians intersect at the centroid, dividing the triangle into three smaller triangles of equal area.
The sum of lengths of any two sides of a triangle is:
A
Greater than the third side
B
Less than the third side
C
Equal to the third side
Analysis & Theory
By the triangle inequality theorem: sum of any two sides > third side.