Help with finding the missing measure to a right angle triangle.?

I need some help with my L.E.A.P. practice. How do you find the missing measurement of part of a right triangle. Example 1: A 250 foot cable runs from the top of a radio antenna to a stake that is 217 feet from the center of the base of the antenna. How tall is the antenna?The hypotenuse is given. Example 2: A tree that is 30 feet tall casts a 45 foot shadow on the ground. What is the distance from the top of the tree to the top of its shadow? The hypotenuse is NOT given. If you are wondering, LEAP is the standardized test for Louisiana, to get to high school. This, I believe is worked with the Pythagorean Theorem. Please answer the problems above for you to show how to this.