Cosine - examples

  1. Ratio iso triangle
    iso_triangle_2 The ratio of the sides of an isosceles triangle is 7:6:7 Find the base angle to the nearest answer correct to 3 significant figure.
  2. Triangle ABC v2
    triangles_4 Area of the triangle is 12 cm square. Angle ACB = 30º , AC = (x + 2) cm, BC = x cm. Calculate the value of x.
  3. Side c
    trig-cos-law In △ABC a=3, b=8 and ∠C=70°. Calculate length of the side c.
  4. Cosine
    cosine The point (21, 20) is on the terminal side of angle θ. cos θ = ?
  5. Trigonometric functions
    trigonom In right triangle is: ? Determine the value of s and c: ? ?
  6. Cuboid
    cuboid_3 Cuboid ABCDEFGH with 10 cm height has a base edge length 6 cm and 8 cm. Determine angle between body diagonal and the base plane (round to degrees).
  7. Regular 5-gon
    5gon_2 Calculate area of the regular pentagon with side 11 cm.
  8. Trigonometry
    trigonometry If you know that cos(α) = sin (-968°), what is the angle α?
  9. Angle between lines
    angle_two_lines Calculate the angle between these two lines: ? ?
  10. Triangle TBC
    isosceles_triangle TBC is isosceles triangle with base TB with base angle 52° and legs length |TC| = |BC| = 30. How long is the base TB?
  11. Circular sector
    vysek_circle I have a circular sector with a length 15 cm with an unknown central angle. It is inscribed by a circle with radius 5 cm. What is the central angle alpha in the circular sector?
  12. Earth parallel
    parallels Earth's radius is 6378 km long. Calculate the length parallel of latitude 50°.
  13. Felix
    astronaut Calculate how much land saw Felix Baumgartner after jump from 22 km above ground. The radius of the Earth is R = 6378 km.
  14. Steeple
    church_tower Steeple seen from the road at an angle of 57°. When we zoom out to 25 meters, it is seen at an angle of 21°. What is high?
  15. Cosine
    theta Calculate the cosine of the smallest internal angle in a right-angled triangle with cathetus 19 and 4 and with the hypotenuse 19.416.
  16. House roof
    roof_pyramid_2 The roof of the house has the shape of a regular quadrangular pyramid with a base edge 17 m. How many m2 is needed to cover roof if roof pitch is 52° and we calculate 9% of waste, connections and overlapping of area roof?
  17. Rectangle
    golden-rectangle-ratio Calculate the length of the side FL and diagonal JL of rectangle JFLB when given: |BL| = 33 cm and angle ∠ JFB = 32 degrees.
  18. Triangle SAS
    triangle_iron Calculate area and perimeter of the triangle, if the two sides are 19 cm and 80 cm long and angle them clamped is 90°.
  19. Building
    building The building I focused at an angle 30°. When I moved 5 m building I focused at an angle 45°. What is the height of the building?
  20. Geodesist
    XY Triangle shaped field (triangle ABC) has side AB = 51 m. path XY is parallel to the side AB which divided triangle ABC into two parts with same area. What will be the length of the path XY? Help please geodesist ...

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