Question

please explain this well i don't understand (55 points)

Answer 1

Answer:

B

Step-by-step explanation:

the area of a triangle is

$A=\frac{1}{2}(h)(b)$

so if we take as

$from\:(x_1,y_1)\rightarrow(x_2,y_1)$

so the base is

$b=x_2-x_1$

so the height is

$from\:b\rightarrow(0,0)$

the distance is

$h=y_1-0$

so the area is

$A=\frac{1}{2}(y_1+0)(x_2-x_1)\\\\=\frac{1}{2}(y_1)(x_2-x_1)$

so the answer is B