If we write all the possible combinations for this problem, 4/16 or 1/4 would be the answer.
BGGG
GBGG
GGBG
GGGB
This is not taking into consideration the specific order of the children. In case the order will be necessary, the Girls need to be labeled differently and permutation formula needs to be used.
1. Check the picture at the bottom.
2. ABCD is a right trapezoid so the diagonals have equal length. Lets find diagonal BD.
3. In triangle ABD we are given the length AB=7, AD=5 and m(A)=80°.
4. We use the cosine law: 
5. Cosine of 80 can be found with a scientific calculator or in the internet as cos80=0,17
6. 
square root of BD=7.88, so the answer is 8 feet.
Answer:
isosceles triangle
Step-by-step explanation: