Area of a triangle = 1/2*b*h
1/2*5*15 = 32.5 units
Area = 0.5*base*height = 37.5 square units.
Area = 1/2*5*15 = 37.5 square units
1/2*15*5 = 37.5 square units
1/2*15*4 = 30 square units
I don't know if this is the most efficient way to get to the answer (short of looking at the back of the book), but here goes: Remove a parallelogram with top and bottom of 15 units from the trapezium. This will leave a triangle with base 23-15=8, and sides of 8.5 and 10. The area of this triangle, in terms of its sides, a, b and c, is sqrt[s*(s-a)*(s-b)*(s-c)] where s = (a+b+c)/2 That is, the area of the triangle is 32.77 square units. Now, the area of the triangle is also base*height/2 So 8*Height/2 = 32.77 That is, Height = 32.77/4 = 8.1925 units
Area = 0.5*base*height = 37.5 square units.
37.5
The area of triangle is : 60.0
multiply the base by the height and divide by two. 5 x 15 = 75/2 = 37.5 units.
Area = 1/2*5*15 = 37.5 square units
It is: 0.5*12*15 = 90 square units
1/2*15*5 = 37.5 square units
1/2*15*4 = 30 square units
A = 1/2 bh 78 square units
An equilateral triangle with a height of 20 has a base of 23.1 (23.09401), not 15. If the base is 15 then the height will be 13 (12.99038).
The formula for finding the area of a triangle is half of the base x the height. For this triangle, it would be 1/2 of 10 X 3, or 15 square units.
Area = Base*Height = 15*12.3 = 184.5 square units.