How do i find to area of a triangle?

Akitchen floor is made up of tiles that are in the shape of the triangle shown there are 40 tiles on the kitchen floor what is the total area of the floor

You and a friend race across a field to a fence and back. your friend has a 50-meter head start. the equations shown represent you and your friend's distances dd (in meters) from the fence tt seconds after the race begins. find the time at which you catch up to your friend. you: d=∣−5t+100∣d=∣−5t+100∣ your friend: d=∣−313t+50∣∣

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?