C言語を使って台形の面積を計算！7ステップで完全解説

#include <stdio.h>

int main() {
    double top, bottom, height, area;

    printf("上底を入力してください: ");
    scanf("%lf", &top);

    printf("下底を入力してください: ");
    scanf("%lf", &bottom);

    printf("高さを入力してください: ");
    scanf("%lf", &height);

    area = (top + bottom) * height / 2;

    printf("台形の面積は: %.2lf\n", area);

    return 0;
}

上底を入力してください: 5
下底を入力してください: 10
高さを入力してください: 8
台形の面積は: 60.00

#include <stdio.h>

double trapezoid_area(double top, double bottom, double height) {
    double area;
    area = (top + bottom) * height / 2;
    return area;
}

int main() {
    double top, bottom, height, area;

    printf("上底を入力してください: ");
    scanf("%lf", &top);

    printf("下底を入力してください: ");
    scanf("%lf", &bottom);

    printf("高さを入力してください: ");
    scanf("%lf", &height);

    area = trapezoid_area(top, bottom, height);

    printf("台形の面積は: %.2lf\n", area);

    return 0;
}

#include <stdio.h>

struct Trapezoid {
    double top;
    double bottom;
    double height;
};

double trapezoid_area(struct Trapezoid t) {
    double area;
    area = (t.top + t.bottom) * t.height / 2;
    return area;
}

int main() {
    struct Trapezoid t1 = {5, 10, 8};
    struct Trapezoid t2 = {6, 7, 9};

    printf("台形1の面積は: %.2lf\n", trapezoid_area(t1));
    printf("台形2の面積は: %.2lf\n", trapezoid_area(t2));

    return 0;
}

台形1の面積は: 60.00
台形2の面積は: 58.50

#include <SDL2/SDL.h>
#include <stdio.h>

// 台形の情報を保持する構造体
struct Trapezoid {
    int top, bottom, height;
};

// 台形の面積を計算する関数
double trapezoid_area(struct Trapezoid t) {
    double area = (t.top + t.bottom) * t.height / 2.0;
    return area;
}

int main(int argc, char* argv[]) {
    SDL_Init(SDL_INIT_VIDEO);              // SDL2の初期化
    SDL_Window *window = SDL_CreateWindow("Trapezoid Area", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_OPENGL);
    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    
    struct Trapezoid t = {100, 200, 150};
    double area = trapezoid_area(t);

    char area_text[50];
    sprintf(area_text, "Area: %.2lf", area);

    // 描画ループ
    while (1) {
        SDL_Event e;
        if (SDL_PollEvent(&e)) {
            if (e.type == SDL_QUIT) break;
        }

        SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
        SDL_RenderClear(renderer);

        // 台形の描画
        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
        SDL_RenderDrawLine(renderer, 100, 300, 200, 200);
        SDL_RenderDrawLine(renderer, 200, 200, 300, 200);
        SDL_RenderDrawLine(renderer, 300, 200, 400, 300);
        SDL_RenderDrawLine(renderer, 100, 300, 400, 300);

        // 台形の面積を表示
        SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
        SDL_Surface *surface = TTF_RenderText_Solid(TTF_OpenFont("arial.ttf", 24), area_text, {255, 0, 0});
        SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, surface);
        SDL_Rect rect = {10, 10, surface->w, surface->h};
        SDL_RenderCopy(renderer, texture, NULL, &rect);

        SDL_RenderPresent(renderer);

        SDL_FreeSurface(surface);
        SDL_DestroyTexture(texture);
    }

    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    
    return 0;
}