Using a student records table, count the number of students registered in MATH subject.
select count(distinct Student_Id) from Student_Records where Student_Subject = "MATH"
In a right triangle ABC, tan(A) = 3/4. Find sin(A) and cos(A). Angle B is the right angle.
As B is right angle, Tan (A) = BC / AB = 3/4. Thus using Pythagorean theorem we can get to AC = 5. Hence, we get the ratio of BC / AC = 3/5 = Sin (A) and AB / AC = 4/5 = Cos (A).
If the diagonal D of a square is 4 units. Find the area of the square.
Since all 4 sides of a square are equal, consider side of a square as 'S'. Then 2 sides of a square and its diagonal form a right angle triangle. So, we use pythagorean theorem and arrive at the following equation (S^2 + S^2 = D^2). This gives us S* 2^(1/2)=D +> S = 4/2^(1/2). So, S = 2 * 2^(1/2). Then Area of a square = Side ^ 2 = (2* 2^(1/2)) ^ 2 = 4* 2 = 8 square units