(please show your working out )Mr. Martin is making a swimming pool in his garden. He has three options, he can either make a triangular swimming pool or a circular swimming pool. In the remaining section outside the swimming pool, he will plant grass seeds to have nice green grass outside the swimming pool area. He will need to work out how much he would have to pay for the grass seed if grass seed comes in bags that cover 20 m2 and costs $10. please I really need this

You drop a rubber ball off the roof of a 50 meter high building onto a paved parking lot. it bounces back up with every bounce, but not quite all the way back up to you. after the first bounce it bounces back only 80 percent of the distance it was dropped from. the pattern continues, meaning after every bounce it comes up to just 80 percent of the previous maximum height. so if before the first bounce the height is 50 meters, what height does the ball reach after the fifth bounce? round your answer to one decimal place and chose the correct response from the choices below: