The USGBC reports that from 2015 to 2018, LEED-certified buildings have saved $1.2 billion in energy savings and $715.2 million in building maintenance costs. If this trend continues at the same rate over the next 15 years, what will be the savings in building maintenance costs between 2018 to 2033? A. $3.576 billion
B. $6.000 billion
C. $10.728 billion
D. $18.000 billion

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq