Here you have an equilateral triangle. Because of this you know that all angles are also the same as each other. We know that the angles in an equilateral triangle are 60°.
so let's set 7x + 4 = 60
Subtract 4 from both sides: 7x = 56
Divide both sides by 7: x = 8
4*d^(-3)*d^18 = 4*d^(18-3) = 4*d^(15). The trick here is to combine the exponents.
Another way to write this problem would be:
4*d^18
---------- . Here d^18 divided by d^3 results in d^15, so again the final
d^3 answer is 4*d^15.
500 = 10x + 2 * 15 * 5 + 15x
500 = 25x + 150
500 - 150 = 25x
350 = 25x
x = 14
Triangular ends: 14 * 10 = 140
Base rectangle: 14 * 15 = 210
side rectangles: 5 * 15 * 2 = 150
140 + 210 + 150 =
66 more min. he used which could be 1 hour and 6 min.
