Giving away free points only asking to help me with number 3 please

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Mrs. blake's bill at a restaurant is $42.75. she wants to leave the waiter an 18% tip. how much will she pay in all, including the tip?

Maria heard on the radio that the high temperature that day would be to determine the temperature in degrees celsius, she used the formula , where c is the temperature in degrees celsius and f is the temperature in degrees fahrenheit.