ZABC and ZDEF are complementary angles.
2 answers:
You might be interested in
First symmetrically cut the octagon to get 8 pieces. (So that you will get the idea that this polygon is divided into 8 triangles)
Then find the area of one of the triangles:
Area of Triangle =
A = × 12 × 19
A = 114 cm²
To find the area of the whole octagon shape:
A = 114 × 8 = 912 cm²
<em>Hope it helps!</em>
Answer:
The lines blue and green are perpendicular
Step-by-step explanation:
we know that
If two lines are perpendicular, then their slopes are opposite reciprocal (the product of their slopes is -1)
The formula to calculate the slope between two points is equal to
step 1
Find the slope of the blue line
we have the points
(-1,-3) and (0,3)
substitute
step 2
Find the slope of the red line
we have the points
(3,-3) and (4,2)
substitute
step 3
Find the slope of the green line
we have the points
(-4,-1) and (2,-2)
substitute
step 4
Compare the slopes
Blue line ---->
Red line ----.
Green line --->
so
The slope of the blue line and the green line are opposite reciprocal ( their product is equal to -1)
therefore
The lines blue and green are perpendicular