Geo problems (60..69)


problems 50..59
problems 70..79
60.



Calculate edges AB and AC.



61.
Given is square ABCD.
DF=a; BE=b;AF=x;
LBAE=LEAF.
Prove that x=a+b;





62.



Calculate radius r of the smallest circle.



63.
Given is square ABCD.
AB=a; FC=FE=b;
Prove that x2=2ab;





64.
Given is right angled triangle ABC with two contacting inscribed circles.
AB=5; BC=4; AC=3;
Calculate radius r of the circles.





65.
Calculate the area of the colored triangle.





66.
Prove the formula for the truncated cone.





67.




68.





69.