# Thread: Trigonometric function/Perimeter

1. ## Trigonometric function/Perimeter

I cannot figure out these two questions.

1. The length of one of the legs of a right triangle is 3 ft. Express the perimeter, p, of the triangle in terms of the length, L, of the other leg.
I have gotten h=3+L, but what do I do from there?

2. (secθ-tanθ)(secθ+tanθ)

2. Originally Posted by cam_ddrt
I cannot figure out these two questions.

1. The length of one of the legs of a right triangle is 3 ft. Express the perimeter, p, of the triangle in terms of the length, L, of the other leg.
I have gotten h=3+L, but what do I do from there?

2. (secθ-tanθ)(secθ+tanθ)
1. You know that the two legs have length 3 and L. Then you have enough information to find the length of the hypotenuse, since the triangle is a right triangle.

2. Difference of squares: $(\sec\theta-\tan\theta)(\sec\theta+\sec\theta)=\sec^2\theta-\tan^2\theta=\frac{1}{\cos^2\theta}-\frac{\sin^2\theta}{\cos^2\theta}.$ It should be easy to simplify from here.