| u | = √(2² + (-1²)) = √5
| v | = √ ( 1² + (-8)² = √65
cos (u,v) = ( u * v ) / (| u | * | v |) =
(2 * 1 + ( -1 ) * ( - 8 )) / √5 √ 65 = (2 + 8) / √5 √65 = 10 / (√5 √ 65 )
The length of a larger diagonal:
d 1² = | u |² + 2 |u| |v| + | v |² = 5 + (2 √5 √65 * 10 / √5 √65 )+65
d 1² = 70 + 20 = 90
d 1 = √ 90 = 3√10
d 2² = 70 - 20 = 50
d 2 = √50 = 5√2
Answer:
The lengths of the diagonals are: 3√10 and 5√2 .
Answer:
upward?
Step-by-step explanation:
U can use the cosine or sine rules depending on the question/triangle
Answer:
12.57
Step-by-step explanation:
the formula for the area of a circle is 
the diameter is 2 times the radius, so dividing it by 2 gives you a radius of 2
substitute the 2 for the r in the formula and solve

4
≈12.57
Answer:
8
Step-by-step explanation:
ahe rented the bike for a total of 8 hours