What is an angle?
It is the opening that forms the intersection of two lines.
- An obtuse angle is one that measures more than 90º.
- An acute angle is one that measures less than 90º.
- A right angle is equal to 90º.
- A straight angle is equal to 180º.
The sum of two angles:
- Two angles are complementary if their sum equals 90°.
- Two angles are supplementary if their sum equals 180°.
What is a rectangle?
A rectangle is a polygon with four sides, with the characteristic that its opposite sides are equal.
What is the measure of the angle formed by the diagonals of the rectangle ABCD?
The area of a rectangle can be determined by knowing its diagonals and the angle they form between them.
A = D² Sen(γ)/2
Being;
Being;
A = (7)(6)
A = 42cm²
Apply the Pythagorean theorem to determine D.
D² = AB² + AD²
replace;
D² = (7)² + (6)²
D² = 49 + 36
D² = 82
Substitute in A;
42=82 Sen(γ)/2
Solve for γ;
84=82 Sen(γ)
γ = Sen⁻¹(84/82)
γ =