Firefighters used a ladder 50 feet high to reach a window that was 30 feet above the ground. from the same point on the ground, the ladder is turned to across the street to reach a window that was 40 feet high.

select all the true statements.

-the width of the street, bm, is 70 feet.
-the ground distance of the ladder from building b is 30 feet.
-the ground distance of the ladder from building m is 30 feet.
-the width of the street, bm, is 122 feet.
-the length kl is 50 feet.

First since 2 of the options ask for the width of BM lets solve for it using the Pythagorean theorem for both sides of point L:
a² + b² = c²
30² + b² = 50²
b² = 50² - 30²
b² = 1600
b = 40    Line BL = 40 ft
Since the ladder is 50 feet it is the same length on the other side as well
a² + b² = c²
40² + b² = 50²
b² = 50² - 40²
b² = 900
b = 30        line LM is 30 ft
SO line lm + line bl = 30 + 40 = 70 ft
A is true because ^
B isn't true because as we solved for earlier, BL is 40
C is true because line LM is in fact 30 ft as we solved for
D is not true because as we said earlier BM is 70
E is true because the same ladder was used on both sides of the street

What do you mean i don’t understand