There are 50 balls in one box. The number of red balls is 30 and the number of blue and yellow balls are 20 . Find the number of blue balls in the box.

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

a

step-by-step explanation:

i agree because i see the other persons thinking is clear

step-by-step explanation:

for volume, add base x height x width