In Figure 3. Triangle ABC is inscribed in a semicircle. If BD=6 and CD=4, what is the area of triangle ABC?
(A) 78
(B) 39
(C) 36
(D) 32
(E) 25​

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25