Trigonometry exercises in third grade are very important for the student. In addition, these ninth grade math exercises on trigonometry are intended for teachers but also for ninth grade students wanting to review the chapter of trigonometry in the right triangle online. From then on, you will learn a new method of calculation. In addition, students must also have the necessary materials to practice properly.
Exercise series on trigonometry
1) Construct a triangle IJK such that :
JK = 8 cm; IJ = 4.8 cm; KI = 6.4 cm.
2) Show that the triangle IJK is a right triangle.
3) Calculate the measure in degrees of the angle .
Give the value rounded to the nearest degree.
Exercise 2 Trigonometry :
1. Paul wants to install a basketball hoop at his house. It must be fixed at 3.05 m from the ground. The ladder he uses is 3.20 m long.
How far from the foot of the wall should he place the ladder so that its top is just level with the basket? (Give an approximate value to the nearest cm).
2. Calculate the angle formed by the ladder and the ground. (Give a value approximated to the nearest degree).
Let ABC be an isosceles triangle with base [BC], [AH] the height from vertex A.
We have: BC = 8 cm and AH = 7 cm.
1) Construct the triangle ABC and justify the construction.
2) Calculate .
3) Deduce the value of the angle rounded to the nearest degree.
Exercise 4 Trigonometry:
The figure below shows a triangle SET isosceles at E, and the height [SH] from S. You are not asked to redo the figure.
We know that the segments [ES] and [ET] measure 12 cm and that the area of the triangle SET is 42 cm2.
1) Show that the measure h of the segment [SH] is equal to 7 cm.
2) Calculate the value of the length EH to the nearest millimeter.
3) Calculate the measure of the angle to the nearest degree.
The unit of length is the centimeter; the unit of area is the square centimeter.
Consider the figure opposite:
- – the triangle ABC is rectangular in A ;
- – AB = 3.6 ;
- – BC = 6.
1) Calculate the measure of the angle (round to the degree).
2) Calculate AC.
3) Calculate the area of triangle ABC.
4) Let H be the orthogonal project of point A on the line (BC).
Express the area of triangle ABC as a function of AH.
5) Deduce AH.
ABCD is a rectangle such that AB = 7.2 cm and BC = 5.4 cm.
1) Draw the rectangle and its diagonal in real size [AC].
2) Calculate the measure, rounded to the nearest degree, of the angle .
3) Show that the angles and are equal.
4) The perpendicular bisector of the segment [AC] intersects the line (AB) at E. Place the point E and show that the triangle ACE is isosceles.
5) Deduce an approximate value for the measure of the angle .
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