Answer:
90°
Step-by-step explanation:
angle on a straight line=180 and half of 180=90°
Thought I already answered this. I must have forgotten to click "add your answer."
We have similar triangle trianges ABC ~ ADE so
BC:AB = DE:AD
BC:2 = 10 : (2+3) = 10:5 = 2:1
So BC=4 because 4:2 = 2:1
Choice C.
<h3><u>D</u></h3>
If ΔXYZ ≅ ΔDEF, then X = D, Y = E and Z = F.
the operation:

Gives a square number.
<h3>
How to get a perfect square?</h3>
A perfect square is the product of a number and itself.
As you can see in the example, 16 is a square number. Then let's try to get 16.
To get 16 we can use the difference:
20 - 4
So the first therm needs to be equal to 20, and the second equal to 4.
To write 20 in scientific notation we have:

To write 4 in in scientific notation:

Then the operation:

Gives a square number.
If you want to learn more about square numbers:
brainly.com/question/21694652
#SPJ1