The base of a triangular pyramid is a triangle with corners at (5 ,1 ), (2 ,7 ), and (3 ,6 ). If the pyramid has a height of 4 , what is the pyramid's volume?

1 Answer
Apr 4, 2017

2 unit^3

Explanation:

Volume of pyramid = 1/3 * base area * height

let say x_1 = 5, x_2 = 2,x_3 = 3, y_1 = 1, y_2 = 7 and y_3 =6

Base area = 1/2 |(x_1*y_2 + x_2*y_3+x_3*y_1) - (y_1*x_2+y_2*x_3+y_3*x_1)|

= 1/2 |(5*7 + 2*6 + 3*1) - (1*2 + 7*3 + 6*5)|

= 1/2 |(35 + 12 + 3) - (2 + 21 + 30)|

= 1/2 |(50- 53)| = 1/2 |(-3)| = 3/2

Volume of pyramid = 1/3 * 3/2 * 4 = 2 unit^3