geometry
posted by Carmen on .
The base length of the triangle with vertices A(1,1, B(9,1), C(5,5)is multipliend by 2.Describe the effect of the change on the area.
can someone help me on this one.. am stuck

A = (b/2) *h,
Multiply the base by 2 and get:
A = b*h,
So the area is doubled.
Let's calculate the area of the given
triangle.
A(1,1), B(9,1), C(5,5).
AB = 9  1 = 8 = base.
(AC)^2 = (51)^2 + (51)^2,
(AC)^2 = 16 + 16 = 32,
AC = sqrt32 = 5.66.
(b/2)^2 + h^2 = (AC)^2,
4^2 + h^2 = 32,
h^2 = 32  16 = 16,
h = 4.
A = (b/2) * h,
A = (8/2) * 4 = 16.
Double the base:
A = (16/2) * 4 = 32. 
The area is multiplied by 4