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

2 Answers
Jan 13, 2018

Volume of a pyramid is # 12 # cubic.unit.

Explanation:

Volume of a pyramid is #1/3*#base area #*#height.

#(x_1,y_1)=(6,7) ,(x_2,y_2)=(2,5),(x_3,y_3)=(3,1) , h=4#

Area of Triangle is

#A_b = |1/2(x1(y2−y3)+x2(y3−y1)+x3(y1−y2))|#

#A_b = |1/2(6(5−1)+2(1−7)+3(7−5))|# or

#A_b = |1/2(24-12+6)| = | 9| =9# sq.unit.

Volume of a pyramid is #1/3*A_b*h = 1/3 *9*4 = 12 # cubic.unit [Ans]

Jan 13, 2018

#"volume "=12#

Explanation:

#"the volume (V) of a pyramid is calculated using the formula"#

#•color(white)(x)V=1/3xx"area of base "xx" height"#

#"the area (A) of the triangle can be found using"#

#•color(white)(x)A=1/2|x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)|#

#"let "(x_1,y_1)=(6,7),(x_2,y_2)=(2,5),(x_3,y_3)=(3,1)#

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

#color(white)(A)=1/2|24-12+6|=1/2|18|=9#

#rArrV=1/3xx9xx4=12#