The base of a triangular pyramid is a triangle with corners at (1 ,3 ), (2 ,2 ), and (8 ,5 ). If the pyramid has a height of 7 , what is the pyramid's volume?

1 Answer
Sep 12, 2017

Volume of pyramid is 10.5 cu.unit.

Explanation:

x_1=1 ,y_1=3 ,x_2=2 ,y_2=2,x_3=8 ,y_3=5

Area of Triangle A_t= 1/2(x1(y2−y3)+x2(y3−y1)+x3(y1−y2)) or

A_t= 1/2(1(2−5)+2(5−3)+8(3−2)) or

A_t= 1/2(-3+4+8)= 9/2 =4.5 sq.unit

Volume of pyramid is V_p=1/3*A_b*h ; where base area

is A_b = A_t= 4.5 , h=7( hight).

:.V_p=1/3*4.5*7 = 10.5 cu.unit.

Volume of pyramid is 10.5 cu.unit. [Ans]