Calculate the area of triangle CDE with altitude EF, given C (3, −2), D (−1, 2), E (2, 3), and F (0, 1).

4 square units

6.2 square units

8 square units

8.7 square units

Question

Calculate the area of triangle CDE with altitude EF, given C (3, −2), D (−1, 2), E (2, 3), and F (0, 1).

 4 square units

 6.2 square units

 8 square units

 8.7 square units

anonymous · Answer

@phi @emilycs713 @israr000

phi · Answer

It might be helpful to plot the points to see what is what.

But to finish the problem you need to know the formula to find the area of a triangle
do you know it ?

anonymous · Answer

I got 8 as my answer! @phi

anonymous · Answer

distance formula right?

phi · Answer

yes, you use the distance formula twice.

anonymous · Answer

Alright, I ended up with 8 as my final answer. Do you know if it is right? I would show my work, but it's on paper, and very hard to put up here. :/

phi · Answer

just say what segments you found the length of:  base and height
and the lengths you found

anonymous · Answer

To calculate the area, you need to multiply one side by an adjacent side. To find the side length, use the distance formula: √(x2-x1)²+(y2-y1)². This will give you the side length, so then you can multiply the two. It helps to draw it out so you know that the sets of coordinates form lines that are adjacent.