The answer is 12.92 in, 12 in, and 11.2 in
The area (A) of the triangle is:
A = s * a / 2
s - side
a - altitude
We know:
A = 84 in²
s1 = 13 in
s2 = 14 in
s3 = 15 in
a1 = ?
a2 = ?
a3 = ?
_______
a1 = ?
A = s1 * a1 / 2
84 = 13 * a1 / 2
84 * 2 = 13 * a1
168 = 13 * a1
a1 = 168 / 13
a1 = 12.92 in
_________
a2 = ?
A = s2 * a2 / 2
84 = 14 * a2 / 2
84 * 2 = 14 * a2
168 = 14 * a2
a2 = 168 / 14
a2 = 12 in
_______
a3 = ?
A = s3 * a3 / 2
84 = 15 * a3 / 2
84 * 2 = 15 * a3
168 = 15 * a3
a3 = 168 / 15
a3 = 11.2 in
9*9=81
2*2=4
81-4=77
77 square feet.
Hope this helps :)
Answer:
it's A
Step-by-step explanation:
AS the location here for studing or taking notes dosen't make any sense or link his exam grades. for the other options we have :
-NO. of taking notes which is bascially the amt. of time he spends.
-time
-scores.
