Conventionally we use uppercase letters to represent each apex, and lowercase letters to represent the angles.
The internal angles of a triangle will sum to 180°.
A regular triangle is called equilateral . All its sides will be of equal length and all its angles will be equal, i.e. all angles will be 60°
A triangle with two sides equal is called isosceles . It will also have two equal angles.
In a Right Angled triangle, the longest side is called the hypotenuse (alternatively, the side opposite the right angle).
a) Find angles marked a and b
a) Find the height of this isosceles triangle
The square of the hypotenuse equals the sum of squares of the other two sides
a) Find the length of the diagonal of the quadrilateral
The basic formula stated for the area of a triangle is