Answer:
D. 11.8 cm
Step-by-step explanation:
This triangle is a 30°-60°-90° triangle. There is a shortcut to find the lengths of the sides of a 30°-60°-90° triangle. The longest side is the hypotenuse. The longest side is double the shortest side or, the shortest side is half the longest side. Here the longest side is 5, so the short leg (shortest side) is 2.5
The other shortcut is that the longer leg is the
short leg×sqroot3
Here, the short leg is 2.5, so the long leg is 2.5×sqroot3
Perimeter is all the sides added together.
5 + 2.5+ 2.5×sqrt3
Do the times first.
5 + 2.5 + 4.3
= 11.8
