Answer:
D2=21/24 mile
Step-by-step explanation:
Her it is not specified if it is base or height, it only talks about dimensions, so let's work with dimensions
A=1/12 
D1=4/21mile, D2=?
Area of a triangle 
A=((D1*D2)/2) → 2A=D1*D2 → D2=2A/D1 so D2=(2*1/12)/(4/21) =(1/6)/(4/21) = (1*21)/(6*4)=21/24 mile
Answer:
9
Step-by-step explanation:
Raise 3 to the power of 2.
Step-by-step explanation:
ABC is an isoceles triangle (both legs are equally long). and AB is its baseline.
OC is now a median for ABC splitting the angle at C and AB in half.
so, we have 2 right-angled triangles : OAC and OBC.
the half-angles at C are 42/2 = 21°.
the angles at A and B are 90°.
and the half-angles at O are 180 - 90 - 21 = 69°.
remember that the sum of all angles in a triangle must always be 180°.
AB are the heights of both of these triangles.
the single height is sin(69)×7 = 6.535062985... cm
and so,
AB = 2× height = 13.07012597... cm.
