the base of an isosceles triangle is 18 centimeters long. The altitude to the base is 12 centimeters long. What is the approximate measure of a base angle of the triangle?

  1. 👍 0
  2. 👎 0
  3. 👁 614
  1. Since it is isosceles, the altitude splits it into two congruent right triangles. The base angle is
    arctan(12/9) = arctan(4/3). It's a "3,4,5" right triangle. Use a table or calculator to get the angle. It's about 53 degrees

    1. 👍 0
    2. 👎 0
  2. The altitude of an isosceles triangle
    is the perpindicular bisector of the
    base and devides the triangle into 2
    congruent rt. triangles. Y=12=altitude, X=18/2=9= 1/2 of base.
    TanB=Y/X=12/9=1.3333, B=53.13 Degrees.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. geometry

    the base of a triangle is 4dm longer than its altitude, and its area is16dm^2. Find the lengths of the base and its altitude.

  2. algebra

    This isosceles triangle has two sides of equal length, a, that are longer than the length of the base, b. The perimeter of the triangle is 15.7 centimeters. The equation 2a + b = 15.7 can be used to find the side lengths. If one

  3. pre calculus

    The base of an Isosceles triangle is half as long as the two equal sides. Write the area of the triangle as a function of the length of the base. the answer is: A=a^2times the square root of 15 ------------------------------ 4 How

  4. geometry

    Each base of an isosceles triangle measures 42 degrees, 30'. The base is 14.6 meters long. a. Find the length of a leg of the triangle b. Find the altitude of the triangle c. What is the area of the triangle?

  1. Calculus

    The base of an isosceles triangle is 8 feet long. If the altitude is 6 feet long and is increasing 3 inches per minute, are what rate are the base angles changing?

  2. geometry

    the diagram below shoes a pennant in the shape of an isosceles triangle. the equal sides each measure 13, the altitude is x+7 and the base is 2x.

  3. Summer Creek

    An isosceles triangle has legs that are each x inches long a base that is y inches long. The perimeter of this triangle is 38 inches. The base is 8 inches shorter than the length of a leg.

  4. algebra

    The base of an isosceles triangle and one of its legs have lengths that have consecutive integers. The leg is longer than the base. The perimeter of the triangle is 20. Find the length of each side of the triangle. *Please help

  1. calculus

    An isosceles triangle is drawn with its vertex at the origin and its base parallel to the x-axis. The vertices of the base are on the curve 5y=25-x^2 Find the area of the largest such triangle.

  2. Geometry

    the legs of an isosceles triangle have lengths 2x+4 and x-8 the base has length 5x-2 whats the lenght of base

  3. Differential Calculus

    The base of an isosceles triangle is 10 feet long and the base angles are decreasing at a rate of 2° per second. Find the rate of change of the area when the base angles are 45°.

  4. math

    the base of an isosceles triangle is 5 and its perimeter is 11. The base of a similar isosceles triangle is 10. What is the perimeter of the larger triangle? ithink the perimeter is 16.

You can view more similar questions or ask a new question.