50 Points and brainliest, simple data

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

In what organelle does photosynthesis take place?

Ateacher wanted to buy a chair, a bookshelf, two tables and a desk. she spent $900 for all five items and the chair and the desk combined 70% of her total. if the bookshelf cost $50, how much did each of the tables cost?