Answer:
16.2
Step-by-step explanation:
The angle internal to the triangle at B is the supplement of the one shown, so is 65°. That is equal to the angle internal to the triangle at D. Since the vertical angles at C are congruent, the two triangles are similar by the AA theorem.
Corresponding sides of similar triangles are proportional, so we can write the proportion shown in the attachment:
BC/FC = DC/AC
BC = FC(DC/AC) = 21.6(7.2/9.6)
BC = 16.2 . . . . matches the first choice
Supplementary angles sum up to 180°, suppose the supplement of 161° is x. Then
161+x=180
solving for x we subtract 161 from both sides
161-161+x=180-161
x=19
thus the supplement is 19°
The answer is a. Because when word phrases say “a number”, they are referring to the variable. For instance, x is the variable so x is “a number”.
Step-by-step explanation:
The coordinate plane is a two-dimension surface formed by two number lines. One number line is horizontal and is called the x-axis. The other number line is vertical number line and is called the y-axis. The two axes meet at a point called the origin. We can use the coordinate plane to graph points, lines
