The sum of the interior angles in any triangle is 90 degrees.

The sum of the interior angles in any triangle is 180 degrees.

The sum of the interior angles in any triangle is 360 degrees.

The sum of the interior angles in any triangle is 270 degrees.

An equilateral triangle is a triangle with one angle that is exactly 90 degrees.

An equilateral triangle is a triangle with at least two sides of equal length and two angles of equal measure.

An equilateral triangle is a triangle where all three sides are of equal length, and all three interior angles are 60 degrees each.

An equilateral triangle is a triangle with all sides and all angles of different measures.

A right triangle has one angle that is exactly 90 degrees.

A right triangle has all sides of equal length and all angles 60 degrees.

A right triangle has one interior angle greater than 90 degrees.

A right triangle is a triangle with all angles less than 90 degrees.

Area is calculated by the formula: base * height.

The area of a triangle is calculated by the formula: 1/2 * base * height.

Area is calculated as base + height.

Area is calculated by height / base.

To find the perimeter of any polygon.

The Pythagorean theorem is used to calculate the length of a side in a right triangle: a² + b² = c², where c is the hypotenuse.

To find the area of a parallelogram.

To determine if angles in a triangle are equal.

An isosceles triangle has all three sides of equal length and all three angles are 60 degrees each.

An isosceles triangle has at least two sides of equal length and two angles of equal measure.

An isosceles triangle has one angle that is exactly 90 degrees.

An isosceles triangle has all sides and angles of different lengths and measures.

A scalene triangle is one with two sides of equal length.

A scalene triangle has all three interior angles less than 90 degrees.

A scalene triangle is a triangle with all sides and all angles of different measures.

A scalene triangle is a triangle where all three sides are of equal length.

The exterior angle theorem states that the measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.

The exterior angle theorem states that an exterior angle is always greater than any interior angle.

The exterior angle theorem states that all angles on the exterior of a triangle sum up to 360 degrees.

The exterior angle theorem states that all exterior angles in a triangle are equal.

If the sum of any two lengths is less than or equal to the third length.

If one length is equal to the sum of the other two lengths.

Three lengths can form a triangle if the sum of any two lengths is greater than the third length (triangle inequality theorem).

If all three lengths are equal, they cannot form a triangle.

An altitude is a line segment that bisects all angles in a triangle.

An altitude is a perpendicular segment from a vertex to the line containing the opposite side or the extension of it.

An altitude is the longest side of a triangle.

An altitude is the sum of all the sides of a triangle.

A median is a line segment joining a vertex to the midpoint of the opposing side, effectively dividing the triangle into two smaller triangles of equal area.

A median is a line that bisects one angle of the triangle.

A median is a perpendicular segment from a vertex to the opposite side.

A median connects all vertices to form a closed loop.

An angle bisector is a line segment from the vertex touching the base twice.

An angle bisector divides a triangle into two congruent triangles.

An angle bisector divides an angle into two equal parts and in a triangle, it will meet the opposite side.

An angle bisector is a line that cuts through the centroid of the triangle.

Both acute and obtuse triangles have all angles equal to 90 degrees.

An acute triangle has all three interior angles less than 90 degrees, while an obtuse triangle has one interior angle greater than 90 degrees.

An acute triangle has one exterior angle while obtuse triangles have two.

An obtuse triangle has all sides equal while an acute triangle has all different.

The perimeter of a triangle is the base times the height.

The perimeter of a triangle is the sum of the lengths of its sides.

The perimeter is half the sum of the triangle's angles.

The perimeter is calculated using the formula: p = 2(length + width).

Heron's formula is used to find the area of a triangle using its side lengths: √[s(s-a)(s-b)(s-c)], where s is the semi-perimeter, or (a+b+c)/2.

Heron's formula calculates the area as base * height / 2.

Heron's formula is just another name for the Pythagorean theorem.

Heron's formula calculates the area as (base + height) / 2.