1. Question 9

2. Question 9
Right triangle ABC and right triangle ACD overlap as shown below. Angle DAC measures 20˚ and angle BCA measures 30˚.
What are the values of x and y?
The students can use a calculator for this problem. Each part of the question (value for x and value for y) is worth one point, so two points total.
On the following slides you can see how to solve for each value of x and y.

3. Question 9 Cont 90 + x + 20 + 30 = 180 140 + x = 180 ______________
This first triangle will be solved for the value of x.
Triangles have 180 degrees, when you add all of the degrees together. In this triangle ABC, we know a few values of it. The degree amount at angle B is 90 (the square in the corner means that it is a right angle and right angles are 90). So, when we add up the degrees within this triangle, we have: x = All of those values within that triangle will equal to We then add them together and we get that x = To solve for x, we subtract 140 from both sides and we get that x = 40.
140 + x = 180
______________
-140
-140
x = 40

4. Question 9 Cont 90 + y + 20 + 30 = 180 140 + y = 180 ______________
This first triangle will be solved for the value of y.
Triangles have 180 degrees, when you add all of the degrees together. In this triangle ACD, we know a few values of it. The degree amount at angle B is 90 (the square in the corner means that it is a right angle and right angles are 90). So, when we add up the degrees within this triangle, we have: y = All of those values within that triangle will equal to We then add them together and we get that y = To solve for x, we subtract 140 from both sides and we get that y = 40.
140 + y = 180
______________
-140
-140
y = 40