If the vertex angle of an isosceles triangle has a measure of 60 and the length of each leg is 18, find the length of the altitude drawn to the base.

Rose98
Jul 9, 2014

#1**+10 **

Ah, lovely, an easy one. Equilateral triangle. After this one I'm eating dinner x3

60 - 60 - 60 means all sides are equal. Altitude splits this one perfectly in half as well, and makes a 30 - 60 - 90 triangle. 30 - 60 - 90 means x - x(squareroot(3)) - 2x.

2x is equal to one of the original legs, which is 18. x is equal to the split leg, or 9. x(squareroot(3)) equals the altitude, and since x = 9, x(squareroot(3)) = 9(squareroot(3))

**9(squareroot(3))** is your answer.

GoldenLeaf
Jul 9, 2014

#1**+10 **

Best Answer

Ah, lovely, an easy one. Equilateral triangle. After this one I'm eating dinner x3

60 - 60 - 60 means all sides are equal. Altitude splits this one perfectly in half as well, and makes a 30 - 60 - 90 triangle. 30 - 60 - 90 means x - x(squareroot(3)) - 2x.

2x is equal to one of the original legs, which is 18. x is equal to the split leg, or 9. x(squareroot(3)) equals the altitude, and since x = 9, x(squareroot(3)) = 9(squareroot(3))

**9(squareroot(3))** is your answer.

GoldenLeaf
Jul 9, 2014