Answer: height =8 miles
Base = 15 miles
Explanation:
A triangle has 3 sides. Easter island is roughly triangular in shape. The height of the triangle is 7 miles less than the base.
Let h = height of triangle
Let b = base of triangle.
h = b-7 - - - - - - 1
Area of triangle = 1/2 base × height
1/2× b × h = 60 - - - - -2
Put h = b-7 in equation 2
1/2×b×(b-7) = 60
b^2-7b = 2×60=120
b^2-7b - 120=0
Solving the quadratic equation,
b^2 +8b -15b -120=0
b(b+8)-15(b+8)=0
b -15 = 0 or b+8 = 0
b =15 or b = -8
b = 15 because the value cannot be negative.
h = b-7 = 15 -7 =8