Dr. black is standing 20 feet from a streetlamp. the lamp is making his shadow 5 feet long. he estimates that the angle of elevation from the tip of his shadow to the top of the streetlamp is 30 degrees. to the nearest foot, the streetlamp is about

Ten times the square of a non-zero number is eqaul to ninety times the number

Atheater wants to build movable steps that they can use to go on and off the stage. they want the steps to have enough space inside so they can also be used to store props. how much space is inside the steps?

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.