The area of the triangle is 90 m²
Explanation:
Given that the base of the triangle is 15 m
The altitude of the triangle is 12 m
<u>Area of the triangle:</u>
The area of the triangle can be determined using the formula,

where b is the base and h is the altitude
Thus, we have,
and 
Substituting the values in the above formula, we get,

Multiplying the terms, we get,

Dividing, we get,

Therefore, the area of the triangle is 90 m²
Perpendicular,
Explanation:
I just drew it down on paper
Answer:
-18 3/4
Step-by-step explanation:
One application of volume is determining the density of an object. Assume the object is made of a pure element (eg: gold). If we know the volume (v) of the object, and we know the mass (m), then we can use the formula D = m/v to figure out the density D. Knowing the volume is also handy to determine if the object can fit into a larger space or not. Another application is figuring out how much water is needed to fill up the inner space of the 3D solid (assuming it's hollow on the inside).
The surface area is handy to figure out how much material is needed to cover the outer surface. This material can be paint, paper, metal sheets, or whatever you can think of really. A good example is wrapping a present and the assumption is that there is no overlap.