How to find an area of a equal triangle? basically what is the formula

You are responsible for designing a new city. you are inspired by pierre charles l'enfant, who laid out the streets of our nation's capital. numbered streets run north and south, and lettered streets run east and west. avenues are named after states, and they intersect the streets on a diagonal. the streets are parallel and the intersections form similar triangles. 18th st. is 454 meters long and the intersection of 18th and k st. is 207 meters from connecticut ave. if 19th st. and k st. is 385 meters from connecticut ave., what is the length of 19th st.?

1. what is the measure of ∠abc? what is the measure of ∠abd?

Aball is dropped from a height of 10m above the ground. it bounce to 90% of its previous height on each bounce. what is the approximate height that the ball bounce to the fourth bounce?