Answer:
Perimeter of ΔABC: + units
Area of ΔABC: units
<u>Skills required: HS Geo, Special Triangles</u>
Step-by-step explanation:
1) The best option is to break down this triangle. Let's draw an altitude from Point B down to Segment AC. The point from the altitude that intersects AC is Point D. BD is the height of our triangle, AC is the base.
2) Angle A is 60 degrees, and since Angle BDA is 90 degrees, Angle ABD is 30 degrees. We can use the 30-60-90 degree right triangle property for the triangle BDA.
- This states that if the side opposite the 30 degree angle is , the side opposite the 60 degree angle is , and the side opposite the 90 degree angle is .
AB is 9 units, and it is opposite the 90 degree angle. This means that ==> This then means that AD, the segment opposite the 30 degree angle in this triangle is units. Segment BD (the height) is .
3) Angle C is 45 degrees, and Angle BDC is 90 degrees, which means that Angle CBD is 45 degrees. We can use the 45-45-90 degree right triangle property for the triangle BCD.
- This states that if the side opposite the 45 degree angle is , the other side opposite a 45 degree angle is also , but the hypotenuse (side opposite the right (90 degree) angle) is .
BD is , which means DC is the same. BC, which is the hypotenuse is BD multiplied by square-root-2, which is .
4) Area is , the base (b) is AC (which is ), the height is BD (). When multiple you will get , then this multiplied by 1/2 is
<--> this is the area!
5) Perimeter is just the sum of all side: 9 + + = + unit