Answer:
x + 52 + 78 = 180
Step-by-step explanation:
By angle sum property of a triangle:

Here's a scenario that you can edit to your own advantage. You own a shirt shop. Each shirt sells for 15 dollars, and to make profit annually you need to sell $62,365 worth of shirts. If you've sold 2,000 shirts so far, how many shirts do you need to meet your quota. How many shirts on average per month would you have to sell?
We set up a proportion: 84/?= 56/100
Cross multiply: 56*?= 84*100
⇒ ?= 84*100/56= 150
56% of 150 is 84.