trigonometric word problem

I am trouble finding the solution to the following problem! Can someone please help me? Thank you!

A ladder is 20 feet long. It leans against a building making an angle of 70 deg. with the ground. How high up on the building does it reach? Report to 1 decimal place?

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sin = opposite / hypotenuse

20' is the hypotenuse of a right triangle formed by the ladder and the building and the ground.

Remember that

In this case opposite is refering to the height of the building where the ladder meets it. And Hypotenuse is refering to the length of the ladder.

So you need to find

sin(70) = .93969...

.93969... * 20' = 18.8'