A right triangle is a triangle in which one angle is straight (is 90 degrees).

Triangle area formula:
where a, b are the legs.

A right triangle is a triangle in which one angle is straight (is 90 degrees).

Triangle area formula:
where c is the hypotenuse, α is the angle between the hypotenuse and the cathet.

A right triangle is a triangle in which one angle is straight (is 90 degrees).

Triangle area formula:
where b is the cathet, α is the angle between the hypotenuse and this cathet.

A right triangle is a triangle in which one angle is straight (is 90 degrees).

Triangle area formula:
where d and e are segments on the hypotenuse formed as a result of an inscribed circle.

A right triangle is a triangle in which one angle is straight (is 90 degrees).

Triangle area formula:
where c is the hypotenuse,r is the radius of the inscribed circle.

A right triangle is a triangle in which one angle is straight (is 90 degrees).

Triangle area formula:
where p is a semiperimeter:

An isosceles triangle is a triangle in which two sides are equal in length. Equal sides are called lateral, and the other is called the base.

Triangle area formula:
where a is equal sides, c is the third side.

An isosceles triangle is a triangle in which two sides are equal in length. Equal sides are called lateral, and the other is called the base.

Triangle area formula:
where a is equal sides, α is the angle between them in degrees.

An isosceles triangle is a triangle in which two sides are equal in length. Equal sides are called lateral, and the other is called the base.

Triangle area formula:
where a is the side, c is the base, α is the angle between them in degrees.

An isosceles triangle is a triangle in which two sides are equal in length. Equal sides are called lateral, and the other is called the base.

Triangle area formula:
where c is the base, α is the angle between the sides in degrees.

An isosceles triangle is a triangle in which two sides are equal in length. Equal sides are called lateral, and the other is called the base.

Triangle area formula:
where c is the base, h is the height.

An equilateral triangle is a triangle with all sides equal to each other.

Triangle area formula:
where a - side of a triangle.

An equilateral triangle is a triangle with all sides equal to each other.

Triangle area formula:
where h is the height of the triangle.

An equilateral triangle is a triangle with all sides equal to each other.

Triangle area formula:
where r is the radius of the inscribed circle.

An equilateral triangle is a triangle with all sides equal to each other.

Triangle area formula:
where R is the radius of the circumscribed circle.

A triangle is a geometric figure consisting of three points (the vertices of a triangle) that do not lie on the same straight line, connected by three segments (the sides of the triangle).

Triangle area formula:
where a is the base, h is the height.

A triangle is a geometric figure consisting of three points (the vertices of a triangle) that do not lie on the same straight line, connected by three segments (the sides of the triangle).

Triangle area formula:
where a and b are the sides, α is the angle between them.

A triangle is a geometric figure consisting of three points (the vertices of a triangle) that do not lie on the same straight line, connected by three segments (the sides of the triangle).

ФTriangle area formula:
where a, b and C - side, r is the radius of the inscribed circle.

A triangle is a geometric figure consisting of three points (the vertices of a triangle) that do not lie on the same straight line, connected by three segments (the sides of the triangle).

Triangle area formula:
where a, b and C - side, R is the radius of the circumscribed circle.

A triangle is a geometric figure consisting of three points (the vertices of a triangle) that do not lie on the same straight line, connected by three segments (the sides of the triangle).

Triangle area formula:
where a, b and c are sides, p is a semiperimeter:

A triangle is a geometric figure consisting of three points (the vertices of a triangle) that do not lie on the same straight line, connected by three segments (the sides of the triangle).

Triangle area formula::
where c is the side, α,β are the angles belonging to it.

Solution:

S =

· a^{2}

=

· 91^{2}

=

· 8281

=

3585.673

Ответ: площадь равностороннего треугольника с стороной 91 equal to 3585.673