Answer:
Explanation:
The area of a triangle is commonly described as one half times the base times the height. A better way to describe it though might be one half times the base times the length from the highest point to the base. A bit more of a mouthful but it helps get rid of confusion in cases like this.
So, the distance from the base to the highest point is 25 mm and the base itself is 11 mm. That 23 doesn't mean anything here and the 35 is the length of one of the sides, but not the base or the height, so it's not used. Anyway, we have the values we need.
(1/2)11 * 25 = 137.5