Which triangles are similar? 5
16
37'
679
12
空
13
12
20
53°
23°
Triangle A
Triangle B
539
15
379
12
Triangle C
O A. Triangles B and C
B. Triangles A and B
O C. Triangles A, B, and C
O D. Triangles A and C

When you are making a circle graph by hand, how do you convert a number for a part into its corresponding angle measure in the circle graph? when you are making a circle graph by hand, what should you do if one of your angle measures is greater than 180°?

Asphere has a diameter of 10 in. what is the volume of the sphere?

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .