It is quite simple problem of a school course. For its decision it is enough to know several protozoa of mathematical formulas which are fundamental in geometry. Also the ability to reflect and consider logically on the calculator is required.
It is required to you
- - minimum data necessary for the solution of a task, namely length of each party and diagonal of a pentagon;
- - calculator;
- - handle;
- - sheet of paper.
Instruction
1. Attentively read an objective condition. Being guided by it, draw an estimated pentagon on the sheet of paper.
2. Designate length of each of its parties.
3. Carry out two diagonals in a pentagon. Designate length of each diagonal.
4. Pay attention to what turned out as a result of carrying out diagonals, and you will see that they break a pentagon into three triangles various among themselves.
5. From top of each triangle carry out height to its basis.
6. Measure length of height lowered on the basis for each triangle.
7. Determine triangles by the formula given below: S = ½ × H × a where S is the calculated area of a triangle; H – height of each triangle; a – triangle basis length.
8. Calculate the area of a pentagon, having put the areas of these three triangles.