The illustrated broken screen is characteristic of excessive pressure being placed upon the iPad screen - potentially, given your description, from something else that was in your backpack. An unprotected screen can be easily damaged if placed in a bag with other objects.
You would be well advised to protect your iPad with a fitted case that incorporates a rigid cover - as this will often (but not always) prevent the type of damage illustrated in your photo. You appear to be using some type of case, but the cover (if present) isn't visible.
The cracks in the screen might suggest that the iPad has been dropped onto its corner. The case may have absorbed some of the impact, but not sufficiently to prevent damage to the screen.
Your iPad will require repair.
For practical purposes, in lieu of repairing and returning your own iPad, Apple usually exchange the iPad for a renewed/refurbished iPad of the same model and specification. The cost of the exchange is the same as would otherwise be charged for repair. Unless you have benefit of an active AppleCare plan, an out-of-warranty repair while expensive will be somewhat less than the cost of a replacement iPad.
As for out-of-warranty repair costs, Apple offers a fixed-price price repair. You can verify eligibility and cost for your region/country here:
iPad Repair & Service - Apple Support
If you have an active AppleCare+ plan, the cost of repair is reduced to a small excess/deductible fee.