Which of these are true about Columbus?

A. He was the first European to arrive in the Americas.

B. He planned to visit the West Indies.

C. He arrived at an island in the Caribbean Sea in October 1492.

D. He thought he was in Asia.

its Multiple choice

D. He thought he was in Asia

Reason:

Columbus set out to prove the world was round.

For these reasons, he figured he could reach Asia by going west, a concept that most of educated Europe at the time thought was daft — not because the Earth was flat, but because Columbus' math was so wrong.

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69