For a triangle ABC, the height AE on the bottom edge BC is 3.2 cm long. Now the bottom edge is increased by 20 cm. How many square centimeters does the area increase?

For a triangle ABC, the height AE on the bottom edge BC is 3.2 cm long. Now the bottom edge is increased by 20 cm. How many square centimeters does the area increase?

It's very simple. The area formula is 1 / 2 of the bottom edge * height, so increase the area s = 1 / 2 * 20 * 3.2 = 32

When the bottom of a triangle is multiplied by 3 and the height is divided by 4, the area is 12 square centimeters
A｛12｝ B｛15｝ C{16} D｛8｝

130503956,
The original area is:
12 × 4 △ 3 = 16 (square centimeter)
Choose C!

If the base of a triangle is increased by 3 cm and the height remains unchanged, the area of the new triangle will be increased by 12 square cm; if the height is increased by 4 cm and the base remains unchanged, the area of the new triangle will also be increased by 12 square cm, and the area of the original triangle will be calculated

S = ab △ 2 the area of a triangle is equal to the base times the height divided by 2
S+12=(a+3)b
S + 12 = a (B + 4) (a + 3) B = a (B + 4) 3B = 4A a = 3 / 4B according to the area formula, B-A = 2
Then a = 6, B = 8, the area of the original triangle is 6x8 △ 2 = 24