SAT Math Practice Question #21988 - SATify | SATify

Home Practice Exams Features Pricing Quick Start Guide About

Loading...

SAT Math Practice Question #21988 - SATify | SATify

#21988

geometry

3d geometry

trigonometry

hard

180 sec

Let $O$ be the center of a regular tetrahedron $A BC D$ . What is the cosine of the angle $∠ A OB$ ?

A.

$\frac{1}{3}$

B.

$- \frac{1}{3}$

C.

$\frac{1}{2}$

D.

$- \frac{1}{2}$

E.

$0$