(1) The value of x is 25
(2) The measure of ∠CBD is 60°
Explanation:
(1) The given two angles are vertical angles. Since, vertical angles are equal, we can add the two angles to determine the value of x.
Thus, we have,

Subtracting 5x from both sides, we have
Adding 10 to both sides , we have,

Thus, the value of x is 25.
(2) It is given that the measure of ∠ABC = (x+7)° and ∠CBD = (2x+14)°
Since, these two angles are supplementary angles and supplementary angles add upto 90°
Thus, we have,

Simplifying, we get,



Thus, substituting the value of x in ∠CBD = (2x+14)° to determine its value.

Thus, the measure of ∠CBD is 60°
Answer:
The total surface area is: 468 in^2 which agrees with answer a)
Step-by-step explanation:
The three lateral faces of the prism are rectangles, and the sums of their areas give:
12 * 10 + 9 * 10 + 15 * 10 = 360 in^2
The area of each triangular base (notice it is a right triangle) is given by:
9 * 12 / 2 = 54 in^2, so we add TWO of these to the three rectangular faces:
Total surface = 360 in^2 + 2 * 54 in^2 = 468 in^2
Sorry for my bad handwriting a notebook lol