Hi there!

Let there be two angles, ∠A and ∠B, that are supplementary to each other. Therefore:
∠A + ∠B = 180°
We can assign ∠B to be the greater angle. Assume ∠A has a measure of x°.
∠A = x°
∠B = x° + 30°
The sum is equal to 180°, so:
x° + (x° + 30°) = 180°
Solve for x°.
2x° + 30° = 180°
2x° = 150°
x° = 75°
Thus, ∠A = 75°.
Since ∠B is 30°, greater:
∠B = 75° + 30° = 105°.
The answer is <span>$494.55</span>
Let's first imagine a circle and calculate its area and then reduce it in half for the area of a semi-circle. Since this opening is above <span>a 30-inch wide door, the circle will have a diameter of 30 inches.
The area of the circle (A) is:
A = </span>π · r²
where:
π = 3.14
r - radius: r = diameter ÷ 2 = 30 ÷ 2 = 15 inches
So, the area of the circle is:
A = π · r² = 3.14 · 15² = 706.5 inches²
The area of the semicircle is half of the area of the circle:
A1 = A ÷ 2 = 706.5 ÷ 2 = 353.25 inches²
Since the stained glass window costs $1.40 <span>per square inch, for 353.25 square inches it will cost $494.55:
353.25 square inches * 1.40 $/square inch = $494.55</span>
Since we have 2 numbers, we'll be square rooting.
All we have to do to find the mean is multiply & square root the products.
30 × 6 = 180

You can use the same process and check my answer if you'd like; I rounded the square root, so you may get a different answer.
Their intersection is 7 because is you look at the coordinates of both A and B they have 7 in common
In triangle, ABD,
AD²= AB²+BD²
AB² = AD²-BD²
AB² = 18²-9² = 324-81 = 243
AB = √243
In triangle, ABC,
AC² = AB²+BC²
AC² = (√243)²+(13)²
AC² = 243+169
AC = √412
AC = 20.29