The information tells us that this triangle is an isosceles triangle meaning two sides and two angles are congruent. Also, this is not a right triangle as the only isosceles right triangle has a ratio of 1:1:2
Let the angles be x. 3x + 4x + 4x = 180 (angle sum property of a triangle is 180 degrees.) 12x = 180 x = 180/12 x= 15 the angles are 45, 60 and 60 it is an isosceles triangle.
The area of a rectangle is found using the formula A=L*W. The area A=12m+18. The width is W=6. The length will be the expression where 6 times it gives 12m+18. The expression is 2m+3 since 6(2m+3) = 12m+18.