Can a triangle be formed from side lengths 7 m, 10 m, and 20 m?

Yes; 5 + 7 > 10, 5 + 10 > 7, and 7 + 10 > 5 

No because if you add 7 and 10 that is less than 20 so it can not form a triangle

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.