a boy sitting on a platform 7.5m high he observes that the angle of elevation of the top of the opposite building is 40°.the platform is 37.5m away from the building .find the height of the building

Onnie is considering doing some long term investing with money that she inherited. she would like to have $50,000 at the end of 30 years. approximately how much money would lonnie need to put into an account earning 6% interest compounded annually in order to meet her goal?