Answer:
∠?=40°
Step-by-step explanation:
Remember that in a line AND a triangle there are <u>180 degree</u>s.
You correctly found the third angle in the left triangle to be 69°, Now plug it into the equation for a line, including 71°:
<u>69°+71°+x=180°</u>
1) Combine the degrees:
140°+x=180°
2) Subtract 140° from both sides:
x=40°
We have now found the bottom left angle for the triangle on the right to be 40°
To find the angle labeled "?" You must plug in all of the known angles of the triangle to be equal to 180°:
40°+100°+x=180°
1) Combine the degrees:
140°+x=180°
2) Subtract 140 from both sides:
∠?=40°
It takes 45 seconds. the easiest way to do these is to use a graphic calculator and replace the variables with x and y, for example, this equation would become -5x^2+30x, and if you don't have access to a graphing calculator, you can always use desmos online.
Answer:
option C : 2
Step-by-step explanation:
because there can be one triangle from BA till 20cm . and other till D
hope it helps you