Answer:
930
Step-by-step explanation:
1) Once upon a time there was a bored kid in class who invented a super cool formula
This formula goes like this:
n(n+1)
where n= the sum of the first n numbers in a series
so
30(30+1)=30(31)=930
930
Answer:
60
Step-by-step explanation:
because half of children is 50. 120÷50=60
Answer:
Step-by-step explanation:
Triangle BCD is a right angle triangle.
From the given right angle triangle
BC represents the hypotenuse of the right angle triangle.
Taking 45 degrees as the reference angle,
BC represents the adjacent side of the right angle triangle.
BD represents the opposite side of the right angle triangle.
To determine BC, we would apply trigonometric ratio
Cos θ = adjacent side/hypotenuse side. Therefore,
Cos 45 = BC/2√2
√2/2 = BC/2√2
BC = 2√2 × √2/2
BC = 2