The analysis process is as follows:

In a right triangle, one of the three lines, four chords and five chords has an angle of 53 degrees. As shown in the figure below:

Sin∠A=4/5, angle A=53 degrees, from which tan53=4/3 can be obtained.

Extended data:

Properties of right triangle:

1, the sum of squares of two right angles of a right triangle is equal to the square of the hypotenuse.

2. In a right triangle, two acute angles are complementary.

3. In a right triangle, the median line on the hypotenuse is equal to half of the hypotenuse (that is, the outer center of the right triangle is located at the midpoint of the hypotenuse, and the radius of the circumscribed circle R=C/2). This property is called the hypotenuse midline theorem of right triangle.

4. The product of two right angles of a right triangle is equal to the product of hypotenuse and hypotenuse height.

Basic relations of trigonometric functions with the same angle

Reciprocal relations: tanα cotα= 1+0, sin α CSC α = 1, cos α secα =1; +0;

The relationship of quotient: sinα/cosα=tanα=secα/cscα, cos α/sin α = cot α = CSC α/sec α;

Relationship with: sin? α+cos？ α= 1、 1+tan？ α = seconds? α、 1+cot？ α=csc？ α;

Square relation: sin? α+cos？ α= 1。