Question 1177805
Let the base be 21 and the altitude is 12, because A=(1/2)bh
the second triangle has 10 x the base and 10 x the altitude, so the area will be 100 x as much or 12,600 units ^2.
Draw a 3-4-5 right triangle.
The area is 6 units ^2, (1/2)(4*3)
if the triangle were 30-40-50, the area would be (1/2)(1200)=600 units^2