What is the probability of getting a vowel if you randomly pick a letter from the English alphabet?

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).

Let f(x) = 1/x^2 (a) use the definition of the derivatve to find f'(x). (b) find the equation of the tangent line at x=2

The perimeter of ? cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.