Suppose a ladder 20 feet long is placed against a vertical wall 20 feet high. how far would the top of the ladder move down the wall by pulling out the bottom of the ladder by 5 feet?

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

The areas of two similar triangles are 72dm2 and 50dm2. the sum of their perimeters is 226dm. what is the perimeter of each of these triangles?

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?