

Geometry problems 9 (80..89) 


problems 70..79
80.
In picture below AB=AC=AD
Calculate angle x.
81.
In picture below three equal circles are laying tight in perpendicular triangle ABC.
Calculate radius r of the circles.
82.
In a square circles with radius R and r lay tight between quarter circles.
Center of quarter circles lay on vertex of square.
Calculate the ratio R/r.
83.
Prove that the area of triangle ABC is [ABC] = pq
84.
Calculate angle x.
85.
Two lines separate square ABCD in three equal parts.
The distance of the lines is 1.
Calculate the area of the square.
86.
Below is pictured a regular hexagon and a random point inside.
Calculate area x.
87.
Calculate the shaded area A.
88.
Calculate the shaded area.
89.
Calculate the ratio of green/orange square areas.

