What is the volume of the triangular pyramid shown below?
17 cm
10 cm
12 cm

Is the orthocenter of a triangle on the inside ?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?