Big Ideas Math Integrated I, 2016
BI
Big Ideas Math Integrated I, 2016 View details
Chapter Test
Continue to next subchapter

Exercise 11 Page 435

Draw the vertices and polygon in a coordinate plane.

Perimeter: ≈ 17.6
Area: 15

Practice makes perfect

We start by marking the vertices and the polygon in a coordinate plane.

Now we see that it's a triangle.

Perimeter

We determine one of the line segments by counting squares.
To find the other lengths we use the Distance Formula.
JL = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)
JL = sqrt(( -1- 2)^2 + ( 3-( -2))^2)
Evaluate
JL=sqrt((-3)^2+(3-(-2))^2)
JL=sqrt((-3)^2+5^2)
JL=sqrt(9+25)
JL=sqrt(34)
JL=5.83095...
JL≈5.8
One of the sides is about 5.8 units. Now we calculate the length of the third.
KL = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)
KL = sqrt(( 5- 2)^2 + ( 3-( -2))^2)
Evaluate
KL=sqrt(3^2+(3-(-2))^2)
KL=sqrt(3^2+5^2)
KL=sqrt(9+25)
KL=sqrt(34)
KL=5.83095...
KL≈5.8
The third side is also about 5.8 units.

The perimeter of the triangle is therefore approximately 6+5.8+5.8 = 17.6.

Area

The area of a triangle can be found by multiplying the base and height and then dividing by 2.

The base is 6 units and the height is 5 units. Therefore, the area is A=6*5/2=15.